Use factoring to find the zeros.

x2 - 9x - 36 = 0

Answer: x=12, x=-3

Step-by-step explanation: For this factored problem, you see that - 36 is negative, as well at - 9. This shows you that you need to find two numbers that multiply to get - 36, and add up to get - 9. Two numbers that both satisfy these requirements are - 12 and 3. They multiply to get - 36, and add to get - 9.

Once you have found your values, you plug them into (x+ / - __) (x+ / - __), which is (x-12) (x+3).

But since the problem asks you to find the zeroes, you set each factor equal to zero, like this:

x-12=0 and x+3=0

Then solve and you have you answer!