How do you solve the equation #4x^2-28x+49=5# by completing the square? Precalculus Linear and Quadratic Functions Completing the Square 1 Answer Dean R. Jun 1, 2018 #4(x^2-7x + (7/2)^2 )=5-49+4(7/2)^2# #4(x-7/2)^2=5# #(2x - 7)^2 = 5# #x = 1/2 ( 7 pm sqrt{5} ) # 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 3304 views around the world You can reuse this answer Creative Commons License