How do you solve the quadratic 9y^2+6y-8=0 using any method? Precalculus Linear and Quadratic Functions Completing the Square 1 Answer Barney V. Feb 13, 2017 y=2/3 or y=-4/3 Explanation: 9y^2+6y-8=0 :.(3y-2)(3y+4) :.3y-2=0 or 3y+4=0 :.3y=2 or 3y=-4 :.y=3/2 or y=-4/3 substitute y = 3/2 :.9(2/3)^2+6(2/3)-8=0 :.9(4/9)+12/3-8=0 :.4+4-8=0 :.8-8=0 substitute y =-4/3 :.9(-4/3)^2+6(-4/3)-8=0 :9(16/9)-24/3-8=0 :.16-8-8=0 :.8-8=0 Answer link Related questions What does completing the square mean? How do I complete the square? Does completing the square always work? Is completing the square always the best method? Do I need to complete the square if f(x) = x^2 - 6x + 9? How do I complete the square if f(x) = x^2 + 4x - 9? How do I complete the square if the coefficient of x^2 is not 1? How do I complete the square if f(x) = 3x^2 + 12x - 9? If I know the quadratic formula, why must I also know how to complete the square? How do I use completing the square to describe the graph of f(x)=30-12x-x^2? See all questions in Completing the Square Impact of this question 2766 views around the world You can reuse this answer Creative Commons License