Question

How do you factor `25z^4 - 5z^2 - 12`?

Answer 1

Use substitution

Explanation:

Substitute `x= 5z^2` to simplify the expression to become
`x^2 - x -12`
`=(x-4)(x+3)`
Substituting back gives
`(5z^2 - 4)(5z^2+3)`