need math help?

Question

if f(x)=x(x+3)(x-1),use interval notation to give all values of x where f(x)>0.

Answer 1

(1, infinity symbol), right?

Because if f(x) has to be >0, then if x < or = 1, then the last term (x-1) would either be 0 or negative, and since order of operations in multiplication doesn't matter, anything multiplied by 0 or a negative number will be either equal to zero or will be negative.