catrionac catrionac 30-08-2019 Mathematics contestada Select all of the following that are quadratic equations. 7x^2 + 14x = 0 x^3 - 3x^2 + 1 = 0 5x - 7 = 0 x^2 + 3x -5 = 0 x - 5 = 9x + 7 x^2 - x = 3x + 7