Help with SAT Math question!

Test Preparation SAT Preparation
1

<p>I don't know why SAT math question are so difficult and POINTLESS!</p>

<p>If y= 2/3x , which of the following is an expression for ||y|| in terms of x?</p>

<p>A) 2/3x^3
B) 4/9x^2
C) 4/9x^3
D) 8/27x^2
E) 8/27x^3</p>

<p>The answer key says D, I think it is B. What is up with the double bar for absolute value btw. Is it of any significance?</p>

<p>Any reason why the answer is D</p>

2

<p>Uhh wait I forgot…</p>

<p>For any number x, ||x|| = 2/3x^2 btw… its one of those two part questions.</p>

3

<p>Nevermind FIGURED IT! Ugh so basically 2/3x = y and the x, ||x|| = 2/3x^2 means </p>

<p>2/3 (2/3x)^2 = 2/3(4/9x^2) = 8/27 x^2</p>

4

<p>I’m going to assume that when you wrote 4/9x^2 or anything this way, you actually meant (4/9)x^2.</p>

<p>y = (2/3)x
||y|| = (2/3)y^2; plug in (2/3)x for y
= (2/3)[(2/3)x]^2;
= (2/3)(4/9)x^2;
= (8/27)x^2</p>

5

<p>^you don’t need the parenthesis. They do not change the problem</p>