Question 255423
 find an equation of 2 numbers that sum is 15 and product is 54. 
------------
x + y = 15
x*y = 54
---------
y = 15-x
Sub for y in 2nd eqn
x*(15-x) = 54
{{{15x - x^2 = 54}}}
{{{x^2 - 15x + 54 = 0}}}
(x-6)*(x-9) = 0
x = 6
x = 9