To be solved: 4x(x-7)-5x(x-6)=-3 STEP 1: EXPAND 4x(x-7) - 5x(x-6) = -3 4x^2 - 28x - 5x^2+30x = -3 STEP 2: SIMPLIFY basically collect and add the like terms (4x^2 - 5x^2) + (-28x + 30x) + 3 = 0 -x^2 + 2x + 3 = 0 Now this is a quadratic in x STEP 3: SOLVE -x^2 + 2x + 3 = 0 you need to find the factors that would give you a product of -3 and addition of 2 i.e., x1*x2 = -3 (1) x1+x2 = 2 (2) where x1 and x2 are your solutions To mutually satisfy equations (1) and (2) x1 = 3 and x2 = -1 now to check x1*x2 = 3*-1 = -3 x1 + x2 = 3 + (-1) = 2 This now solves your equation for x as x = 3 or -1