SOLUTION: Sum of two digits of a 2-digit number is 7. If the digits are reversed, the new number so formed decrease by 27 . find the number
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Question 1080008: Sum of two digits of a 2-digit number is 7. If the digits are reversed, the new number so formed decrease by 27 . find the number Found 2 solutions by ankor@dixie-net.com, ikleyn:Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! let a = the 10's digit
let b = the units
:
10a + b = the number
:
Sum of two digits of a 2-digit number is 7.
a + b = 7
If the digits are reversed, the new number so formed decrease by 27 .
10a + b = 10b + a + 27
10a - a = 10 - b + 27
9a = 9b + 27
simplify, divide by 9
a = b + 3
a - b = 3
find the number
Use elimination
a + b = 7
a - b = 3
-----------Addition eliminates b, find a
2a = 10
a = 5 is the first digit
you can do the rest
