How do you solve for x in x^2+5x=36

First we want to set the equation equal to zero by subtracting 36 from each side ...

x^2 + 5x - 36 = 0

Now we factor

(x + 9) (x - 4) = 0

Now set each expression equal to zero and solve ...

x + 9 = 0 x - 4 = 0

x = - 9 x = 4

Your solution set is

(-9, 4)