How do i factor s^2+9s=-20

To factor you have to do this:

s^2 + 9s = - 20

+ 20 + 20

s^2 + 9s + 20 = 0

now you need to numbers that multiplied give you 20

and then those same 2 numbers have to add to 9

5 x 4 = 20

5 + 4 = 9

(x + 4) (x + 5)

that means that x = - 4, and - 5