What number that needs to be added to both sides of the equation x^2 + 4x = 96x2+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 xx term by 22, then square the result. This number will be added to both sides of the equation. For the quadratic equation x^2+4x=96x2+4x=96, the coefficient of the xx term is 44. So (4/2)^2=4(42)2=4.

x^2+4x+4=96+4x2+4x+4=96+4

x^2+4x+4=100x2+4x+4=100

(x+2)^2=100(x+2)2=100

Take the square root of both sides.

x+2=+-10x+2=±10

Subtract 22 from both sides.

x=-2+-10x=2±10

Solve for xx.

x=-2+10=8x=2+10=8

x=-2-10=-12x=210=12

x=8, -12x=8,12