Solve the following equation by transforming it into a perfect square trinomial.

x² - 14x = 15

{-22, 36}

{57, 71}

{-1, 15}

{-15, 29}

X^2 - 14 x = 15

(x - 7) ^2 - 49 = 15

(x-7) ^2 = 64

x - 7 = - or + 8

x = 15 or - 1

Just take half o the coefficient of x and subtract it squared as above.

In general

x^2 + ax = b

(x + a/2) ^2 - a^2/4 = b