so we need to factor it into (ax+b)(cx+d)
since we have 1x^2, a and c=1
so factor into (x+b)(x+d)
if we expand, we get
[tex](x+b)(x+d)=x^2+(b+d)x+bd[/tex]
so we need 2 numbers that add to get the middle number and multiply to get the last number
I would factor the last number and see which ones add to the middle one
what 2 numbers multily to get 72 and add to get 17?
hmm, list factor of 72 and add them
1+72=73, nope
2+36=38, nope
3+24=27, nope
4+13=17, yep
so it facotrs to (x+4)(x+13)
