ksp wrote:

Question source :

tough-inequation-ds-what-is-the-value-of-integer-x-93008.htmlThe question is

What is the value of integer x ?

(1) 4 < (x-1)*(x-1) < 16

(2) 4 < (x+1)*(x-1) < 16

I have a doubt with that of choosing option 1.

4 < (x-1)*(x-1) < 16

4 < (x-1)^2 < 16

Taking square root.

2 < (x-1) < 4

When you take the square root (which you can because all terms are positive), you get

2 < |x - 1| < 4

If x is to be an integer, |x - 1| = 3

x can be 4 or -2

Remember, \(\sqrt{x^2}\neq x\)

Instead, \(\sqrt{x^2}\) = |x|

_________________

Karishma

Private Tutor for GMAT

Contact: bansal.karishma@gmail.com