Is h^2 = h?

[VJesus12]

Is \(h^2 = h?\)

(1) \(h + h = h\)
(2) \(h - h = h\)

[spoiler]OA=D[/spoiler]

Source: GMAT Prep

[Brent@GMATPrepNow]

Is \(h^2 = h?\)

(1) \(h + h = h\)
(2) \(h - h = h\)

Target question: Is h² = h?

Statement 1: h + h = h
Subtract h from both sides to get: h = 0
If h = 0, then h² = h becomes 0² = 0 (WORKS!)
The answer to the target question is YES, h² = h
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: h - h = h
Simplify left side to get: 0 = h
If h = 0, then h² = h becomes 0² = 0 (WORKS!)
The answer to the target question is YES, h² = h
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer: D

Cheers,
Brent