Just add their right sides: f(x) + g(x) = "right side of f(x)" + "right side of g(x)" f(x) + g(x) = (16-x²) + (4-x) Now simplify: f(x) + g(x) = 16 - x² + 4 - x f(x) + g(x) = 20 - x² - x Arranging in descending order f(x) + g(x) = -x² - x + 20 Edwin