To make x^2 + 2x a perfect square we need to add the term { 2 / (2*1) }^2
which equals 1.
Add 1 to both sides: x^2 + 2x = 8
add 1 to both sides: x^2 + 2x + 1 = 8 + 1 (x + 1)^2 = 9
Take square root on both sides: x + 1 = +/- 3 x = +3 - 1 or x = -3 - 1 x = 2 or x = -4