Question

Which expressions are equivalent to 4x^4-9x^2?
(could be more than one answer.)
A. (2x^4-3x^2)(2x^4+3x^2)
B. 4x^2(x^2-5)
C. x^2(4x^2-9)
D. (2x^2-3x)(2x^2+3x)

halp plz

Answer 1

We can cosider this to be  a difference of 2 squares  so 

4x^4 - 9x^2 = (2x^2 - 3x)(2x^2 + 3x)   so D is one answer

also we could take x^2  out and get 
x^2(4x^2 - 9)  = C