2 numbers equal 12 when added these same 2 numbers equal 9 when multiplied?

x+y=12 x*y=9 so y=9/x and substituting we have x+9/x = 12, multiply by x and we have: x2 + 9 = 12x or in standard form: x2 - 12x + 9=0 which solving using the quadratic equation gives: (+12 - sqrt(144-36))/2 and (12 + sqrt(144-36))/2 which gives x= 11.196, y = 0.804 and x= 0.804 and y = 11.196 You can search wikipedia for the quadratic equation.