Question

5x^2-9 when x = -2

5(-2)^2-9

I know the answer is 11, but how? When I did it, I got -29 and I don’t know how to get 11. Could someone explain step by step on how to get the correct answer?

Answer 1

5(-2)² - 9

First, solve the one in the bracket which is -2 × -2 which gives us =4

5(4) - 9

Then, multiply 5 with 4 so

20 - 9

Then you'll get 11