SOLUTION: The sum of the digits of a certain two-digit number is 15 while the product is 56. Find the numbers involving quadratic equation.

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: The sum of the digits of a certain two-digit number is 15 while the product is 56. Find the numbers involving quadratic equation.      Log On


   

Question 894092: The sum of the digits of a certain two-digit number is 15 while the product is 56. Find the numbers involving quadratic equation.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
A%2BB=15
A%2AB=56
From the first equation,
A=15-B
Substitute into the second,
15-B%29B=56
15B-B%5E2=56
B%5E2-15B%2B56=0
%28B-7%29%28B-8%29=0
Two solutions:
B-7=0
B=7
then,
A=56%2F7=8
and
B-8=0
B=8
then,
A=56%2F8=7
The two numbers are 7 and 8.