Question

What number needs to be added to both sides of the equation in order to complete the square?

x^2+16x=18

x^2+16x+___ =18+____

Answer 1

x2 + 16x + 82 = 18 + 82

Answer 2

Answer:

64.

Step-by-step explanation:

We have been given an equation $x^2+16x=18$. We are asked to complete the square for the given equation.

We know that to complete a square, we add half the square of x term to both sides of equation to complete square.

We can see that coefficient of x term is 16.

$(\frac{b}{2})^2=(\frac{16}{2})^2=8^2=64$

Add 64 on both sides of equation:

$x^2+16x+64=18+64$

$x^2+2*8x+8^2=82$

$(x+8)^2=82$

Therefore, 64 needs to be added to both sides of the equation in order to complete the square.