To factor ax^2+bx+c, you look for two factors of a and two factors of c, one factor of a multiple one factor of c, the other factor of a multiple the other factor of c, the sum of the two products makes b in this case, the two factors of a is 1 and 2, the two factors of c, -36, are -12 and 3. Write them in the following format: 1 -12
2 3 do a "cross-times", that is, 1 times 3, 2 times -12 (1 multiple 3) +(2 multiple -12)=-21 if you don't get a -21, try other factors of -36, switch the factors up/down till you find the right fit. so (x-12)(2x+3) is the anwer
