3x^2 - 125x + 1300
It's a 3 on the x^2. 3 only factors to 3 and 1, so the answer should look like this:
(3x )(x )
How does 1300 factor? What does 3 * one number plus 3 * the other number look like?
100 * 13, 313, 139
50 * 26, 176, 128
25 * 52, 127, 181
10 * 130, 160, 400
20 * 65, 125, 215
Ah, there's our middle term- the 125. So our answer should look like this:
(3x 65)(x 20)
The 125 is a -, so the answer should look like this:
(3x - 65) (x - 20)
Check that by expanding it, see if we get the original problem:
3x^2 - 60x - 65x + 1300
3x^2 - 125x + 1300
We get the original problem, so the answer checks out.
Answer: (3x-65)(x-20)