SOLUTION: The sum of two numbers is 20. Their product is 36. If the smaller number is represented by x, which of the following represents the larger number?

Algebra ->  Problems-with-consecutive-odd-even-integers -> SOLUTION: The sum of two numbers is 20. Their product is 36. If the smaller number is represented by x, which of the following represents the larger number?       Log On


   

Question 980015: The sum of two numbers is 20. Their product is 36. If the smaller number is represented by x, which of the following represents the larger number?
Answer by Cromlix(4381) About Me  (Show Source):
You can put this solution on YOUR website!
Hi there,
x + y = 20
xy = 36
......
Using xy = 36
y = 36/x
Substitute in
x + y = 20
x + 36/x = 20
Multiply through by x
x^2 + 36 = 20x
Rearrange into ax^2 + bx + c = 0 form
x^2 - 20x + 36 = 0
Factorise
(x - 2)(x - 18)= 0
x - 2 = 0
x = 2
or
x - 18 = 0
x = 18
Hope this helps:-)