So to factor this, you have to realize a few factors.
•You have to find two numbers that multiply to make the last number (36) and add up to the second number (-12b).
•Since the last number in the equation (36) is positive, and the second number in the equation (-12b) is negative, you know that you will have to multiply two negative numbers to get 36, because the two numbers have to add to -12.
So when looking at factors of 36 -
1, 36
2, 18
3, 12
4, 9
6, 6
Looking here, 6 and 6 would be the most to be the answer.
You turn these negative and =
-6 x -6 = 36
-6 + -6 = -12
Answer: (x - 6) (x - 6) or (x - 6)^2