The area of the rectangle is 24, what is the perimeter? (HINT: think quadratic equation)

[@TheClockworkCrow]

Yo dude ty so much i forgot this during the year but since im studying for finals I need to learn this but you explained this really well.

[@panlomito]

No calculator needed: Area = 24 units² = W . (W+5) so W² + 5W = 24 or W² + 5W - 24 = 0 factoring ( W + 8 ) . ( W - 3 ) = 0 so W = -8 or W = 3 Negative solution is not possible so W = 3 units and L = W + 5 = 3 + 5 = 8 units Checking: 3 . 8 = 24 units² -> OK. Perimeter = 2 . ( L + W ) = 2 . ( 3 + 8 ) = 22 units

[@contessa.adella]

I managed x squared + x. 5x =24 But forgot my school Quadratic stuff. So failed…but I was pleased with the little conceptual jump there! The fascinating question would be to not discard the -ve length answer….

[@thomassicard3733]

So, the actual problem is NOT 'area of the rectangle is 24, what is the perimeter?'. Many possible answers to that question!!! Sides are 6 and 4: perimeter is 20. Sides are 24 and 1: perimeter is 50! and so on. Gotta figure that the question is actually this: "Given a rectangle with one side of length x, another side of lenght x + 5, and an area of 24, what is the perimeter?"

[@joshuagibson5121]

I was thinking the same thing until I saw the drawing of the rectangle.

[@Flights-gq8po]

Factor x square + 5x - 24 = 0 Eliminate the negative one and then x must be 3 then substitute and get P=22

[@joshuagibson5121]

Factoring, when possible, is the most common way to get to the answer; however, if factoring is not possible, not only will using the quadratic formula work, completing the square is another tool to get to the answer.

[@danieldennis9831]

x•(x+5)=24 X^2+5x-24=0 (x+8)(x-3)=0 X=-8 is null x=3 Width=3 length=8 perimeter=2(l+w)=22 .. At first I misread .. But checking fixed my mistake.

[@martingriffin5084]

I solved it by looking at the area 24, thinking that is either 3 x 8, 12 x 2 or 6 x 4... 8 - 3 = 5, so that fits the bill, 8+3=11 multiply that by 2 and you have 22.

[@MrHailteam]

Keep in mind there are general fundamentals of the laws of physics

[@johngray2875]

Found quickly it just looking factors of 24 that had a difference of 5. Quadratic formula comes up with the same result. X = 3, X + 5 = 8. The perimeter is 22 either way.

[@v1cut60]

Actually I did use the quadratic formula and I got the correct result within a minute. I don’t see what’s the problem of using the quadratic formula vs factoring or anything else. The result is what really counts.

[@rogeraffleck8677]

There are many problems that must be factored that don't involve the quadratic formula.

[@bobcornwell403]

I came up with 22. I was not able to solve this using algebra. OK. Now I get it. I failed to put 0 at the other side of the equal sign.

[@dwaipayandattaroy9801]

2 ( L+b) = 22

[@robertakerman3570]

It's John's show of course; in the time it takes to send viewers to go learn this/that He could have just demo'ed the procedure.

[@alext8828]

@@robertakerman3570 Agreed.

[@cliftonbrown8764]

X=3.5

[@MrHailteam]

120

[@ed-jf3xh]

It took 3 seconds, ish. Quadratic equations?

[@robertakerman3570]

I have very long 1st's. My 2nd's take much longer(ha-ha)

[@MrHailteam]

I'll say 20 at a glance

[@krysswaters31]

You make math even more boring. Stop talking so much and get to the point and teaching how to solve bro.

[@TarunPlayz.]

Awsome

[@tammisnooke4278]

Stars 5 minutes and 20 seconds into the video. Good video. Takes too much time talking about other stuff eg stars smile faces.

[@asiyamalik6636]

what a confusing explaination. Could have been simplified by keeping it simple. Too much bragging for the first good 3 minutes. wow...

[@thefrogman2246]

Now if x was 2 that would make area 14 (wrong) If x was 3 that would make area 24 $BINGO$ Now I will watch the video This is the guess it and try it method. Spreadsheet could not do this example faster.

[@KaveshSeecharan]

Taking to long