X^2+14x-15=0 solve by completing the square

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