How do you factor #m^4 - n ^4#?
What we have is a difference of squares. Recall that if we have an expression
This has an expansion of
Let's rewrite our expression as
Since we have a difference of squares, we can rewrite this as
What we have in purple is a sum of squares, which can't be factored with real numbers, but we have another difference of squares in blue.
Factoring this, we get
Hope this helps!