Question

Which of the following numbers must be added to complete the square in the equation below?

x²+18x= -27


A. 18 B. 9 C. 54 D. 81

Answer 1

I’m pretty sure the answer is 54

Explanation:

The top answer seemed to only do the first step in the equation but if you take 81 and subtract it by -27, the complete answer equals 54. NEVERMIND!!! after reading the question again, 81 is most likely the correct answer.

Answer 2

First, take half of the coefficient of 18x then square it.

18 / 2 = 9
9^2 = 81

So, D. 81 is the answer.