Algebra
posted by Elise .
How does 3x(4x+5)5(4x+5) factor out to be (4x+5)(3x5) ? This may be wrong, because I wrote this answer in my notes, but could some one please explain this to me? Also, do you have any tips on factoring? I understand the concept when I see an example(Usually), but I have a very hard time actually doing it.

You have two different terms (3x and 5) that both multiply (4x + 5) . You can add these two terms together into (3x  5)
You are using the "distributive" rule that
(x + y)z = xz + yz
but in this case you are using it "backwards".
x, y and z can be constants or algebraic terms