Solve the following equation: 21x 2 = 4(2x + 1)

Given, 21x 2 = 4(2x + 1). ⇒ 21x 2 = 8x + 4 ⇒ 21x 2 - 8x - 4 = 0 ⇒ 21x 2 - 14x + 6x - 4 = 0 ⇒ 7x(3x - 2) + 2(3x - 2) = 0 ⇒ (7x + 2)(3x - 2) = 0 ⇒ 7x + 2 = 0 or 3x - 2 = 0 ⇒ 7x = -2 or 3x = 2 ⇒ x = - or x = . Hence, roots of the given equations are .