Ljchen121,

this is about three consecutive positive (x-1 > 0 => x > 1) number x-1, x, x+1. It is evident, only one of these can be divisible by 3

So from Statements :

(1) (x^2 + x)(x + 1) is divisible by 3.

=> x (x+1) (x+1) is divisible by 3.

=> Either x OR x+1 is divisible by 3.

=> It implies (x-1) can't be divisible by 3

=> SUFFICIENT

(2) x(x^2–x) is divisible by 3.

=> x (x) (x-1) is divisible by 3.

=> Either x OR x-1 is divisible by 3.

=> It implies (x-1) may or may not be divisible by 3

=> NOT-SUFFICIENT

Answer is A

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