If you’re trying to solve the equation 12s + 18 you can’t but if you are trying to factor it, 6(2s+3)
If quadratic formula - s = -3/2
Step By Step - for factoring you find factors of 12 & 18 which both include 6 which you can take out then include the variable s into 2s since you took it from the 12 but not the 18