Question

A number consists of two digits. the sum of the digits is 10. on reversing the digits of the number, the number decreases by 36. what is the product of the two digits?

Answer 1

A number consists of two digits.
let a = the tens digit
let b = the units
then
10a+b = the "number"
:
The sum of the digit is 10.
a + b = 10
:
On reversing the digits of the number, the number decreases by 36.
10b + a = 10a + b - 36
Combine like terms
10b - b = 10a - a - 36

9b = 9a - 36
simplify, divide by 9
b = a - 4
-a + b = -4
:
use elimination on the two equation
a + b = 10
-a + b = -4
------------------addition eliminates a, find b
2b = 6
b = 3

Hope This Helps :)