Subtract x^2 from both sides x^2 + 3x - 7 = 5x + 39 Subtract 5x from both sides x^2 - 2x - 7 = 39 Add 7 to both sides x^2 - 2x = 46 Complete the square by adding (b/2)^2 to both sides, b = ( -2) (-2/2) = -1, then square that (-1)^2 = 1 x^2 - 2x + 1 = 46 + 1 Simplify the expression by factoring (x - 1)^2 = 47 Take square root on each side x - 1 = (sqrt (47)) Solve for x x = 1 + (sqrt (47)) Since 47 is prime, 47 cannot be broken down by the square root and this is the answer to your problem.