Starting equations x *y = -5 (1) x + y = 5 (2) From equation (2), express y = 5 - x and substitute it into equation (1). x*(5-x) = -5. Simplify 5x - x^2 = -5, x^2 - 5x - 5 = 0. Solve quadratic equation using the quadratic formula= = = . The numbers are = 5.854101966 and -0.854101966. ANSWER CHECK. 5.854101966*(-0.854101966) = -5.0000000000 with at least 10 decimals after the decimal dot.