Question

How do you factor `9c^2 - 25d^4`?

Answer 1

`9c^2-25d^4=(3c-5d^2)*(3c+5d^2)`

Explanation:

`9c^2-25d^4=(3c)^2-(5d^2)^2`

`3c=a`
`5d^2=b`

`(3c)^2-(5d^2)^2=a^2-b^2`

`a^2-b^2=(a-b)*(a+b)`

`9c^2-25d^4=(3c-5d^2)*(3c+5d^2)`