Hi Mile, In your PWN Math Book Fourth Edition on page 87 question 5, I do not understand why 6.5 changed to negative 6.5 when you took the absolute value of both sides. Wouldn’t it stay 6.5? Thank you

Woops! Forgot part of first equation in question just submitted. Here is the full question:

(x + 2)^2 + (y – 3)^2 = 40
y = -2x + 4

Which could be the x-coordinate of a solution to the system of equations above?

A) √7

B) √35 / 2

C) (6 + 2√34) /5

D) (4 + 2√191) /5

Could you please explain number 7 on page 29?

Hi Mike. I had a question about question 10 on page 218 from your PWN 4th edition Math guide book. If percent means divide by 100, why is it 8 x10^-4 instead of 8 x 10^-8? I thought I had to divide 8 x 10^-6 by a 100. Could you clear this up for me?

On SAT Practice Test 8, I got marked incorrect on Question 7 of the Math No-Calculator section. This is because I said -1 is a valid solution when it isn’t supposed to be. However, if you plug in -1 into the original equation, and say that the square root of 4 is -2, the solution remains true.

So my question is, on the SAT, are you only ever supposed to use the principle square root of numbers? Saying that the square root of 4 = -2 is what rendered my answer incorrect.

This is a question from April 2018 QAS, Calculator Section, Problem 29.

I can’t figure out why choice D is the correct answer. I was stuck bw choice A and B, and picked A. Why is A wrong and D correct?

Thank you!