Question

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

x2 + 8x = 4

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Answer 1

Add 16 to each side

Explanation:

x^2 + 8x = 4

To complete the square, we take the coefficient of the x term, divide by 2, and then square it

8

8/2 =4

4^2 = 16

Add 16 to both sides of the equation

x^2 +8x +16 = 4+16

(x+4)^2 = 20

Answer 2

16

Explanation:

1/2 the linear term (which in this case is 8x) squared.

The linear term is one which may have a number in front of the x, but there is only 1 x.

x^2 does not qualify as a linear term

So for this question

1/2 8 = 4 leave off the x.

squared = 4^2 = 16

You would add 16 to both sides.