can anyone help me with these:
3x2 + 17x + 10
5y8 - 125
a2 - 2ab - 15b2
4c2 - 12c + 9
5 y^8 - 125 = 5(y^8 - 25)
y^8 - 25 can be written
(y^4 - 5)(y^4 + 5)
For the others, you need to try a few factors until you find a pair that works. For example,
a^2 - 2ab - 15b^2 = (a+3b)(a-5b)