If the solutions of f(x)=0 are 1 and -2, then the solutions of f(2x)=0 are

Question

a)1 and 2
b) 1/2 and -1
c) 2 and -4
d)-2 and 4
2)-1/2 and -1

Answer 1

If the solutions are 1 and -2, and assuming f(x) is a polynomial, then
f(x)=k(x-1)(x+2)
and
f(2x) = k(2x-1)(2x+2)
implying
2x-1=0 or (2x+2)=0
Solve for x.