Question

find all zeros
f(x)=9x^4-25x^2

Answer 1

start with \[x^2(9x^2-25)\] and then factor the second term as the difference of two squares

Answer 2

i factord it already

Answer 3

what do i do with x^2? :O

Answer 4

Set x^2=0
Set 9x^2-25=0
Solve both equations