Solve each of the following equations by using the method of completing the square:

8x^{2} - 14x - 15 = 0

Given: 8x^{2} - 14x - 15 = 0

16x^{2} - 28x - 30 = 0 (multiplying both sides by 2)

16x^{2} - 28x = 30

(adding on both sides)

using a^{2} - 2ab + b^{2} = (a - b)^{2}

(taking square root on both sides)

Hence the roots of equation are

7