Answer
x=4
Work Step by Step
The coefficient of x is -2.
Adding the square of half the coefficient of x creates a perfect square.
$(-2\div2)^2=(-1)^2=1$
$x^2-2x=8$
Add the square of half the coefficient of x to each side of the equation.
$x^2-2x+1=8+1$
Simplify.
$x^2-2x+1=9$
Factor the polynomial.
$(x-1)^2=9$
Take the square root of each side.
$\sqrt{(x-1)^2}=\sqrt 9$
Simplify.
$x-1=3$
Add 1 to each side.
$x-1+1=3+1$
Simplify.
$x=4$
