Question

Factor 5x^4 - 405m^4

Answer 1

factor out the 5
5(x^4-81m^4)
= 5((x^2)^2 - (9m^2)^2)

now use the fact that a^2-b^2 = (a-b)*(a+b)

Answer 2

let me know what you get @Geodripp

Answer 3

Okay thanks :)

Answer 4

then you will use that fact again

Answer 5

Okay so I think I got it. -5(3m-x)(3m+x)(9m^2-x^2)