When you’re solving a system of equations using elimination, you want one of the variables to cancel out so you only have one variable left. When you have only one variable left, you can solve for that variable. It’s like if I had x + y = 10 and -x + y = -2. If I add those equations together, the x and -x will cancel out. x + y + -x + y = 10 + -2 2y = 8 y = 4 In the problem above, multiplying the bottom equation all by -1 changes the y to a -y. Then, when we add the two equations together, the y and -y will cancel out leaving just x’s. And then we can solve for x.
@just_us62844 күн бұрын
Really important question how would you do the negatiave but with completing the square. The question is 11 plus 8x minus x^2
@YouCanLearnMathwithAlyssa4 күн бұрын
When you’re doing completing the square, it is incredibly important that the first term be a plain, positive x^2. Always always always divide everything by whatever coefficient is in front of the x^2 first to get rid of it before you start completing the square. Whether that’s a -1, a fraction, whole number, whatever, divide every term in the equation by that coefficient to get rid of it. So for -x^2 +8x+11=0, divide it all by -1 to change it to x^2 -8x -11=0 then go through the usual steps to complete the square
@just_us62844 күн бұрын
@@YouCanLearnMathwithAlyssathank you so much!! I was so confused:) really help full
@YouCanLearnMathwithAlyssa4 күн бұрын
Glad to help! 😊. I just remembered I have a video on completing the square that you might find helpful as well. It’s at kzbin.info/www/bejne/poLMn5lnm7Wnl5I
@Gameoholic_5 күн бұрын
Are there any other good tests I can take to study for the digital SATS? Because there are only about ~5 in the official Bluebook app. (and I don't want to study from non-digital-sats because they won't be accurate) Thank you!
@YouCanLearnMathwithAlyssa5 күн бұрын
I think the Princeton Review will let you access some of their digital SAT’s if you buy one of their prep books (The hard part right now is that the fully digital SAT is so new that it looks like a lot of test prep companies haven’t had a chance to make comparable practice tests yet) I’ll also add that non-digital-SATs are a great way to zero in on any concepts you need to practice, but I totally agree that practicing with digital SATs is absolutely essential 😊
@Gameoholic_5 күн бұрын
@@YouCanLearnMathwithAlyssa Thanks!!
@Gameoholic_5 күн бұрын
Heya, thank you so much! Quick question- Are there any other good tests I can take to study for the digital SATS? Because there are only about ~5 in the official Bluebook app. (and I don't want to study from non-digital-sats because they won't be accurate)
@YouCanLearnMathwithAlyssa5 күн бұрын
I think the Princeton Review will let you access some of their digital SAT’s if you buy one of their prep books (The hard part right now is that the fully digital SAT is so new that it looks like a lot of test prep companies haven’t had a chance to make comparable practice tests yet) I’ll also add that non-digital-SATs are a great way to zero in on any concepts you need to practice, but I totally agree that practicing with digital SATs is absolutely essential 😊
@3makakram1156 күн бұрын
amazing video, keep it up 🤩
@premgood26 күн бұрын
thank you mam,i have watched many videos but i can't understand but your's was use and i understand
@YouCanLearnMathwithAlyssa6 күн бұрын
That makes me so happy to hear it helped! 😊
@jamesmyrthong61128 күн бұрын
❤❤❤❤❤❤❤ AMAZING
@YouCanLearnMathwithAlyssa8 күн бұрын
Thank you so much - I’m so glad it helped! 😊
@SEANROBLOXEPIC10 күн бұрын
Thank you so much! new nothing for ap summer work now its crunch time. 😆
@YouCanLearnMathwithAlyssa10 күн бұрын
You’re very welcome - always glad to help! 😊
@user-pf4ph9os2d13 күн бұрын
omg thank you so much i love u
@YouCanLearnMathwithAlyssa13 күн бұрын
Aw you’re very welcome 😊
@joegagliardi398416 күн бұрын
80+ x+ x+ 2x= 360 4x=280 x= 70(AC) 2x= 140(CD) 80, 70,70, 140 ( all 4 arcs) Inscribed angles ABC and BCD= 1/2(70arcs)= 35 degrees. My answer, with omitted degree and arc symbols, 2 years later. Let’s hope I’m right. You should continue making videos; I’ve watched many different KZbin teachers over the years and you’re far better than most. Take care!
@YouCanLearnMathwithAlyssa15 күн бұрын
Aww thank you so much for the kind words! 😊
@yousefashour901217 күн бұрын
What if it asks for the minimum?
@YouCanLearnMathwithAlyssa17 күн бұрын
If a problem says “what is the minimum amount…” of something, you want to be using greater than or greater than or equal to in your equation. This can be confusing to students, since “greater than” and “minimum” sound like opposites. But what we’re saying is “if this is the absolute minimum value, then all the possible answers must be *greater than* that”
@sarah-dq5rl18 күн бұрын
I found multiple explanations for this problem, but none made sense until this one. Thank you :D
@YouCanLearnMathwithAlyssa18 күн бұрын
Aw thank you so much! Knowing I was able to help honestly brightens my day 😊
@blessinglillian19 күн бұрын
can I ask a question? So, I'm doing functions, and I'm now at "2x - 4y = 8." I'm trying to isolate y, so I know I need to subtract 2x. Later on in the problem, I have -4y = -2x + 8. I know I now have to divide all terms by -4. How come I have to divide by -4 and not -4y? How come I had to subtract -2x from the initial "2x - 4y = 8" instead of subtracting just 2?
@YouCanLearnMathwithAlyssa19 күн бұрын
We have to subtract 2x and not just 2 because when we’re adding or subtracting we can’t split terms up. That’s because we have 2 x’s, not a 2 and an x. So if we’re trying to isolate y, we need to move both of those x’s to the other side. So we subtract both x’s - or in other words subtract 2x. Now multiplication and division are different. When I have 4y, I am saying I have 4 y’s - and it’s another way of saying “4 times y”. It’s just like how “3 times 2” is the same as 3 2’s or 2 3’s. Now “3 times 2” is 6. If I divide 6 by 2 what do I get? 3. So dividing “3 times 2” by 2 gets me back to 3. And that’s why dividing “4 times y” or “4y” by 4 will leave you with just y. And that’s our goal in these type of problems. Hope this helps! 😊
@W.W.J.D.123 күн бұрын
would this have 3 roots if you were to solve for them further? so probably x=5,x=7 and i don’t know about the -1
@YouCanLearnMathwithAlyssa23 күн бұрын
Here’s a quick rule of thumb for the number of roots - the maximum number of roots a “standard” function can have is the highest exponent you see. So if x^2 is the highest exponent, the function could have up to 2 roots. If it’s x^3, it could have up to 3 roots, etc. It may have less, but it won’t have more. The -1 here doesn’t affect the number of roots - it still only has 2 roots 😊
@univers316225 күн бұрын
thank you for your videos ! you are a life saver.
@YouCanLearnMathwithAlyssa25 күн бұрын
Aw I’m so glad they helped! 😊
@OverclockingCowboy25 күн бұрын
People nowadays do not do subtraction. They would graph the given function. Then, they would graph each function in the answer choices to see which one matches the given function. It works! So this question does not really mean anything anymore. It does not test how you deal with exponents or like terms.
@OverclockingCowboy25 күн бұрын
They can make this question more interesting by asking: What is the total number of people that are not managers? People nowadays solve this problem using Desmos. They have no idea how to do algebraic manipulations. They would graph the function and look for the value of the function at x = 7. If they want to know the number of people who are not managers, they would look for the y intercept. SAT is now a Desmos proficiency test.
@OverclockingCowboy25 күн бұрын
You got lucky by identifying a = 6 from the answer choices. The giveaway here is the graph itself. It is showing a vertical asymptote at x = -4. Thus, f(x) has the form a / (x+4). For f(x+4), the only possible answer is Choice C.
@OverclockingCowboy26 күн бұрын
There is another way. Just plug in the answer choices. C and D are too far off. You only need to try A and B. This kind of problem won’t be around anymore because of Desmos.
@OverclockingCowboy26 күн бұрын
This should be your favorite problem. It has a known solution floating in the clouds. We can quickly derive a+b+c as f(1) = a + b + c We know that the vertex is located at f(9). For the parabola to open upward, f(1) > f(9). In other words, a+b+c > -14 So, Choice D.
@OverclockingCowboy26 күн бұрын
You are the first one I saw that knows how to take the mean of the difference. Everybody is taking the mean of A minus the mean of B. Good job! Here is another explanation: [3(20-19) + 4(30-29) + 7(40-39) + 9(50-49)] / 23 = 23/23 = 1
@PS-te7qcАй бұрын
Nice method
@spazmatic05Ай бұрын
thank you
@YouCanLearnMathwithAlyssa29 күн бұрын
You’re welcome- and thanks for visiting my channel
@sonderenceАй бұрын
I’m an upcoming senior who absolutely flunked the math portion of my SAT last year, and I’m looking to improve my score. Going through the practice tests for me has been incredibly difficult as I tend to break down when I don’t understand something. Your channel has helped me in ways I cannot fully express. Not only do I now understand the math, but my anxiety is significantly lessened because of how reassuring you are. The way you point out when questions are as simple as they appear, but also sympathize and express how you can see how one may be tripped up by it is so unique. I haven’t seen such an attitude from other channels I’ve tried. Thank you so much, I’m a lot more confident now and I’m looking forward to retaking the SAT!
@YouCanLearnMathwithAlyssa29 күн бұрын
Oh my goodness, I think this is the nicest comment I’ve ever received 🥺. Thank you so much for all the kind words- and I’m so happy the videos helped you! 😊
@Pixelpandas910Ай бұрын
you are so funny!
@YouCanLearnMathwithAlyssaАй бұрын
Aw thank you! 😊
@scorpio6319Ай бұрын
Too much nonsense talk get to the point
@pokemongofan8952Ай бұрын
My weak concepts grewed and became stronger thank mam❤
@lynnch5544Ай бұрын
ALYSSA I LOVE YOU you saved my friend and me However, I don't understand why you used 19 instead of 20. and 29 instead of 30
@YouCanLearnMathwithAlyssaАй бұрын
This has to do with what we see written in the word problem, not what we see on the chart. On the chart it absolutely looks like that first bar in Data Set B goes from 10-20. However, the text tells us that it represents numbers greater than or equal to 10, but LESS than 20. That’s why when we’re looking for the biggest possible number represented by that first bar in Data Set B, 19 is as high as we can go. And that’s going to apply all the way down the line.
@3runjoshАй бұрын
this is great! thank you! natural teacher
@YouCanLearnMathwithAlyssaАй бұрын
Ah you’re very kind to say that - I’m so glad it helped! 😊
@sail2byzantiumАй бұрын
Thank you, thank you for this! I was mystified by the answer key explanation (compounded by tiny type all condensed into one massive paragraph) not understanding the difference in numbering (3 x 20 vs. 3 x 19, etc.) Okay, I think I get it now based on the question "what is the SMALLEST possible difference between the mean of data set A and the mean of data set B. Thus choosing the smallest possible terms in the bars of A and the largest in B (so the 3 integers in the first bar of A = 20 and the 3 integers in the bar of B = 19. The smallest difference: 20 - 19 and too 30 - 29, 40 - 39, etc.). Can't thank you enough for clarifying this. I happily learned something today! PS: I assume if the question asked for the LARGEST difference, for the first bars of A and B, respectively we'd have (3 x 29) (from A) - (3 x 10) from B as the first group and going from there. (4 x 39) - (4 x 20), (5 x 49) - (5 x 30), etc.
@YouCanLearnMathwithAlyssaАй бұрын
Yes that’s it exactly 😊. For “biggest difference” we would be lowering Data Set B’s mean and raising Data Set A’s mean as much as possible to increase that gap between them. And I totally understand what you mean about the answer key explanations. After I’ve taken the test myself and prepared my explanations I’ll go check out theirs - I can’t tell you how many times I’ve been like “what on earth…?” 😂 Anyways, I’m so glad this video helped - happy studying! 😊
@sail2byzantiumАй бұрын
@@YouCanLearnMathwithAlyssa Thank you so much! This is really wonderful!
@nazianawshin3511Ай бұрын
omgg thank you so much. The second option is so much easier and understandable. I watched so many videos about this same exact problem but your video helped me alot. THANK YOU.
@YouCanLearnMathwithAlyssaАй бұрын
Aw I’m so happy to hear that it helped! 😊
@YouCanLearnMathwithAlyssaАй бұрын
At 9:59, I say that you get -0.5 when it should be -0.25. Sorry about that - and a big thank you to @edw2 for spotting it and letting me know! 🙂
@edw2Ай бұрын
Great video thank you
@edw2Ай бұрын
I got -0.25 versus-0.5 ?
@YouCanLearnMathwithAlyssaАй бұрын
Just double checked - you’re absolutely right! That was a mistake on my part - sorry about that. Thank you so much for pointing it out - I’ll add a pinned comment to let others know 😊
@rishanjalirajedash4513Ай бұрын
Can you pls proof RHS theorem as well . your explanation is really good
@YouCanLearnMathwithAlyssaАй бұрын
I’ll add it to the queue! 😊
@coolkidsclubsss3860Ай бұрын
👍
@YouCanLearnMathwithAlyssaАй бұрын
😊🙏
@emmabraid4138Ай бұрын
I don't understand how taking the smallest mean of A and the largest mean of B results in the smallest possible difference. Why does that result in them being close? Wouldn't you have to use the smallest mean from both and subtract?
@YouCanLearnMathwithAlyssaАй бұрын
Let’s say I told you “Pick one number that’s between 1 and 10. Now pick another number between 11 and 20. And make sure there’s the smallest possible difference between them.” If you just picked the smallest number between 1 and 10 and then the smallest number between 11 and 20 you’d get 1 and 11. The difference between them would be 10. However, if you picked the biggest number between 1 and 10 but the smallest number between 11 and 20, you’d get 10 and 11. The difference between them would be only 1, which is a way smaller difference than the 10 before. That’s what we’re doing here. We’re making B have the largest mean possible and A have the smallest mean possible so those two means are super close together and have the smallest difference possible.
@emmabraid4138Ай бұрын
@@YouCanLearnMathwithAlyssa Thank you for the detailed explanation on the logic! This makes so much more sense.
@EngrBoyeАй бұрын
Bro SAT is this easy😂 I was literally learning this in grade 6 (but not the function part)
@YouCanLearnMathwithAlyssaАй бұрын
That’s awesome that you’ve got these core concepts down solid! 😁👍 The SAT ramps up as it goes along (and will get harder if you’re doing well on the early questions), so if you’re planning on taking it I’d recommend trying one of their adaptive practice tests to get a good feel for all the concepts you’ll be tested on 😊
@sail2byzantiumАй бұрын
Lordy, lordy, lordy, THANK YOU for explaining that. And thanks for the apt critique that this is really less of a math problem than a semantics (i.e., verbiage) problem. First time to have found you--but definitely subscribed.
@YouCanLearnMathwithAlyssaАй бұрын
You’re welcome - so glad I could help! 😊
@SebastianSoongАй бұрын
Could you plug in x=0 and get y=9?
@YouCanLearnMathwithAlyssaАй бұрын
Absolutely! 😊 That’s one of the things I love about math - there’s often more than one way to reach a solution 😄
@hostsnightcoreАй бұрын
thank you
@YouCanLearnMathwithAlyssaАй бұрын
You’re welcome 😊
@rithishrajasuresh640Ай бұрын
i solved it in 4 seconds lmao
@YouCanLearnMathwithAlyssaАй бұрын
That’s awesome! 😊 It’s actually one of the reasons I encourage everyone to practice so much and get the core concepts down cold - the more types of problems you can solve quickly means you have more time to tackle any problems you’re less familiar with.
@samoy499Ай бұрын
I was struggling with the SAT practice, and I kept searching for videos, so I came across your channel, and you really have helped me understand these practice problems. I really appreciate it. You deserve more views and subscribers 💖💖
@YouCanLearnMathwithAlyssaАй бұрын
Aw that’s so kind of you to say - I’m so glad it helped! 😊
@Danny-nw1jkАй бұрын
❤thanks
@YouCanLearnMathwithAlyssaАй бұрын
You’re very welcome - thanks for visiting my channel! 😊🙋♀️
@gmshakir7148Ай бұрын
Honorable Alyssa may you have bundles of energy, stamina, enthusiasm, alongwith knowledge
@gmshakir7148Ай бұрын
Honorable Alyssa now a days I am busy in teaching and get tired and find less or no time to enjoy social media see you again please
@jin_cotlАй бұрын
Yay I finished
@jin_cotlАй бұрын
6:20 is a bit confusing. B = boat’s speed, not boat’s speed in still water. Did you mean that the boat’s speed in still water = boat’s speed? If so, that makes sense as the boat’s pure speed is done through still water. It was confusing that 3C = B but I think I get it now. It was a bit vague
@jin_cotlАй бұрын
14:05 The last part was slightly confusing, the video says that they’re 200 miles apart and leave at 10am precisely. But the work showed the 45 and 55 mph, the new problem didn’t say that the cars traveled individually at 45 and 55. The new problem only stated that they’re 200 miles apart and both left at 10am.
@jin_cotlАй бұрын
11:11 I think it’s 1:20pm instead of 12:20pm, because the second car didn’t move for an hour after the first car left. It took 4.33 hours to catch up after the second car started moving. The calculation only seemed to find how long it took for the car to reach the other car. It didn’t seem to include the wait time of one hour.
@YouCanLearnMathwithAlyssaАй бұрын
For this one there are actually TWO travel times. If you look at the chart, you’ll see that the time for the 50 mph car is “t” and the time for the 65 mph car is “t-1”. So when we solve for t, we’re solving for how long the 1st car traveled, which is 4.33 hours. The second car traveled for t-1 hours, or 3.33 hours. The first car leaves at 8 AM and travels for 4.33 hours, making it 12:20 PM. The second cars leaves one hour later at 9 AM and travels for 3.33 hours, which also makes it 12:20 PM. I hope I explained that in a way that makes sense - please let me know if you have any other questions! 😊
@Danny-nw1jkАй бұрын
Thanks alot i really appreciate😁
@YouCanLearnMathwithAlyssaАй бұрын
You’re very welcome - so glad I could help! 😊
@zanti4132Ай бұрын
Or... you could just take your quadratic, which is 2x² - 24x + c = 0, where c = a bunch of constants which aren't needed to solve the problem, and divide the quadratic by 2 to get x² - 12x + c/2 = 0. For this equation to have only solution, it must be a perfect square, i.e. (x - 6)², therefore x=6.
@OverclockingCowboy25 күн бұрын
That’s the easiest way to solve it in a matter of seconds. Everybody is trying to figure out how to solve problems using Desmos, instead of trying to figure out how to solve the problems.