Question

What number should be added to both sides of the equation to complete the square?

x² + 8x = 4
04
8
16
32

Answer 1

16

Explanation:

The equation for a square is

`(a+b)^(2) =a^(2) +2ab+b^(2)`

as seen in the equation, 2ab = 8x, thus ab = 4. However, you know that the coefficient of x^2 = 1, so b must equal 4. To complete the square, you need to add b^2 instead of just b, so the answer would be 4^2 = 16