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

7x^{2} + 3x - 4 = 0

Given: 7x^{2} + 3x - 4 = 0

49x^{2} + 21x - 28 = 0 (multiplying both sides by 7)

(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

8