How do you solve the equation 2x^2-7x+12=0 by completing the square? Precalculus Linear and Quadratic Functions Completing the Square 1 Answer Binayaka C. May 11, 2018 Solution: x = 1.75 +- 1/4 sqrt(47) i Explanation: 2 x^2 -7 x +12 =0 or 2 x^2 -7 x = -12 or 2 (x^2 -7/2 x )= -12 or 2 (x^2 -7/2 x +49/16 )= 49/8-12 or 2 (x -7/4)^2 = -47/8 or (x -7/4)^2 = -47/16 or (x -7/4)= +- sqrt(-47/16) or (x -7/4)= +- sqrt(47i^2)/4 [i^2=-1] x = 7/4+- 1/4sqrt(47) i or x = 1.75 +- 1/4sqrt(47) i Solution: x = 1.75 +- 1/4 sqrt(47) i [Ans] 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 1633 views around the world You can reuse this answer Creative Commons License