Data Sufficiency

What is x?

(1) y = x^3-1
(2) y=x-1

the algebraic formula here is:
a^3-b^3 = (a-b)(a^2+ab+b^2)
x^3-1 = (x-1)(x^2+x+1)
statement(1): y = x^3-1, alone is not suff
statement(2): y = x-1, alone is not suff
considering both the statements,
x^3-1 = x-1
=>(x-1)(x^2+x+1) = x-1
=>(x-1)(x^2+x+1-1)=0
=>(x-1)(x^2+x)=0
=>(x-1)x(x+1)=0
=> x = 0,1,-1 => x has got three values, the is ambiguity
even if we consider two statements, there is no clarity on x value
Answer "E"