To complete the square we:
• take the coefficient of X
• divide it by 2
• square that number
• then add it to both sides of the equation.
coefficient of x = 14
14 ÷ 2 = 7 then squaring it equals 49
X^2 +14x + 49 = 15 + 49
(x+7) * (x+7) = 64 then taking the square root of both sides:
x + 7 = 8 AND x + 7 = -8
x = 1 and x = -15
