Thanks for those who answered my previous question! I have just one more: x^2-625=0, what is the GCF? How is it deterimined? It does not appear to me that there is one. How would it then be factored and have the zero-product powers applied?

Then, what about 120x^2-34x-21=0 (The same procedures as the one above) Thank you so much again.

for x^2 - 625 =0

it factors to (x+25)(x-25)= 0

take it from there

120x^2-34x-21=0

I used the formula to find the solutions of x=7/12 and x=-3/10

so the factored form must be
(12x-7)(10x+3) = 0