Praxis 5165 Math Practice Question

Praxis 5165 Math Practice Question - MUST KNOW!

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@paulw987 8 ай бұрын

Rather than sometimes interpreting sqrt(25) as 5 and sometimes as +/- 5 (9:00 - 9:40 in video), you could always interpret it (correctly) as 5. For this to work (relative to a problem like x^2 = 25), you would note that sqrt(x^2) = abs(x) [absolute value]. So from x^2 = 25, taking the (principal--i.e., nonnegative) square root of both sides, you get abs(x) = 5. Values of x = 5 and x = -5 satisfy this equation, as one would hope.

@gavindeane3670 7 ай бұрын

Exactly. The other way of expressing it is: x² = 25 therefore x = ±√25 = ±5

@konstantinossimatos3466 2 ай бұрын

3-sqrt(2m+2)=8. Simple mathematics: 2m+2 >=0 (working with Real numbers the under the square root expression must be always greater or equal to zero). Is it possible to subtract a value that is >=0 from 3 and get 8? Solution: 'null'.

@Hewhowalks-fv5mq 8 ай бұрын

Thanks I could get to the end but was unable to remember the principle square root because I knew the result had to be negitive

@erembald2927 8 ай бұрын

I'll stick my head out m= 23/2, rearranging; 3 - 8 = (2m+2)^0.5, therefore; -5 = (2m+2)^0.5, squaring both sides; 25 = 2m+2, resolving for m = 23/2

@erembald2927 8 ай бұрын

damn forget to check it 🙂

@jineenawarburton2660 2 ай бұрын

I am a middle school teacher trying to pass my Praxis 5165 test for my math endorsement. Is this a class for students or for teachers trying to pass Praxis 5165 test? Please advise. I see all of the comments are referring to students, not teachers. I just don't want to spend the money if it's not what will help me personally. I teach 7th & 8th grade Math.

@zackeeu 6 ай бұрын

I am studying for 5165, and I really wanted to like this video and this channel. But there is WAY too much pointless talking here. The math instruction is great, but it's just too inefficeint to deal with. This literally could/should have been a 3-minute vid.

@krunoslavregvar477 8 ай бұрын

d) null (no solutions)

@josephlaura7387 8 ай бұрын

a) 23/2

@Hi-rw8vr 8 ай бұрын

Null. Add 3, you get: √ 2m+2 =8+3=11 Square it 2m+2=121 Subtract 2 2m=121-2=119 Half it m=119/2=59.5 As none of the options work for this, the answer is d) null.

@luisostasuc8135 8 ай бұрын

You wouldn't add 3 to each side, since it's positive, right?

@Hi-rw8vr 8 ай бұрын

@@luisostasuc8135 shoot, you’re right. Fixed version: Add √ 2m+2 3=8+√ 2m+2 Subtract 8 -5= √2m+2 Square it 25=2m+2 Subtract 2 23=2m Half it 23/2=m Therefore the answer is 23/2 However, -5 cannot be the square root of a number. Though (-5)² is 25, the square root is the absolute value and cannot be a negative number. This means the answer is still null.

@thelazyvegan2257 6 ай бұрын

Wouldn't you know the answer is null when you have a square root = to a negative number?

@gavindeane3670 6 ай бұрын

Yes. There's no need to go any further than that. As soon as you have √(something) = (a negative number) then you know you have an impossible equation.

@bravewave2084 8 ай бұрын

Mmm. That was fun. I want some more. Vaguely familiar...

@herbertklumpp2969 8 ай бұрын

Sqrt >=0 conclude. 3- sqrt

@DominicMazoch 8 ай бұрын

Praxis is also a Klingon moon!

@luisostasuc8135 8 ай бұрын

My first quick calculation got 23/2, but then I remembered that negative, and it isn't in the answer that way. It will be interesting to see where i went wrong on this