Is x=1?

[sannamalai]

Is x=1
1) x^3 + x^2 = 2x
2) x not equal to -2

is the answer E or C?

Solving 1, X = -2 or 1. Combining statement 1 & 2, X = 1.
I am getting the answer as C. But not sure about the official answer. (I found this as part of some online GMAT PREP MATH question bank. Answer is given as E. IS that right?>

[RonPurewal]

It's E. You're forgetting that zero is a solution to the first equation.

Factor the first equation:
x^3 + x^2 - 2x = 0
(x)(x^2 + x - 2) = 0
(x)(x + 2)(x - 1) = 0
x = 0, -2, or 1. The (x) term, out front, allows zero to be a factor.

[sannamalai]

It's E. You're forgetting that zero is a solution to the first equation.

Factor the first equation:
x^3 + x^2 - 2x = 0
(x)(x^2 + x - 2) = 0
(x)(x + 2)(x - 1) = 0
x = 0, -2, or 1. The (x) term, out front, allows zero to be a factor.

Thanks Ron. I wish I am able to avoid such obvious mistakes in the exam.

[RonPurewal]

You're welcome.

Don't waste your time labeling mistakes as "obvious", or as "stupid mistakes", or whatever.
What's the point? A mistake is a mistake is a mistake. Just diagnose what's wrong, and figure out how NOT to make that mistake in the future.

For instance, I am personally not very good at subtraction. E.g., if you ask me what 36 - 9 is, my first answer will always be "25", and then I'll have to realize in retrospect that it's 27.
Perhaps this is "stupid", but, who cares. I just know that it's something I personally have to double-check"”regardless of whether others might have to do the same.