Question

Which two numbers have a sum of 15 and a product of 36

Answer 1

Answer:  3  and  12

Step-by-step explanation:

Let x represent one of the numbers and y represent the other number. Then,

Sum:      x + y = 15      →    y = 15 - x

Product: xy  = 36

Use substitution method by replacing "y" with "15 - x" in the second equation, then solve for x:

x(15 - x) = 36

15x - x² = 36

       0  =  x² - 15x + 36

       0  =  (x - 3)(x - 12)

 0 = x - 3     and       0 = x - 12

 x  = 3                       x = 12