How to solve x^2 + 6x = 7:
x^2 + 6x + 9 = 16 << First, find the c term by doing (b/2)^2. (6/2)^2 is 9, so add 9 to both sides of the equation.
(x + 3)^2 = 16 << Factor the left side.
x+3 = plus or minus 4 <<Take the square root of both sides.
x = -3 - 4, -3 + 4 << Subtract the 3
x = -7, 1
