What number that needs to be added to both sides of the equation x^2 + 4x = 96 to complete the square?

1 Answer
Dec 15, 2015

The number to be added to both sides is 4.

Explanation:

Divide the coefficient of the x term by 2, then square the result. This number will be added to both sides of the equation. For the quadratic equation x^2+4x=96, the coefficient of the x term is 4. So (4/2)^2=4.

x^2+4x+4=96+4

x^2+4x+4=100

(x+2)^2=100

Take the square root of both sides.

x+2=+-10

Subtract 2 from both sides.

x=-2+-10

Solve for x.

x=-2+10=8

x=-2-10=-12

x=8, -12