SOLUTION: The sum of the digits of a two-digit counting number is 9. When the digits are reversed, the new number is 45 less than the original number. What is the original number?

Algebra.Com
Question 625518: The sum of the digits of a two-digit counting number is 9. When the digits are reversed, the new number is 45 less than the original number. What is the original number?
Answer by lwsshak3(11628)   (Show Source): You can put this solution on YOUR website!
The sum of the digits of a two-digit counting number is 9. When the digits are reversed, the new number is 45 less than the original number. What is the original number?
***
let u=units digit
let t=tens digit
u+t=9
u=9-t
original number: 10t+u
new number: 10u+t
..
10t+u=10u+t-45
10t+9-t=10(9-t)+t-45
10t+9-t=90-10t+t-45
10t+9-t=90-10t+t-45
18t=36
t=2
u=9-t=7
original number:27
new number: 72

RELATED QUESTIONS

the sum of the digits of a two digit number is 9, when the digits are reversed the new... (answered by mananth)
The sum of a two-digit counting number is 9. When the digits are reversed, the new... (answered by richwmiller)
URGENT HELP: The sum of the digits of a two-digit number is 9. If the digits are... (answered by fcabanski)
The sum of the digits of a two-digit counting number was 9. When the digits were... (answered by Nate,ankor@dixie-net.com)
The sum of the digits in a two-digit number is 8. When the digits are reversed, the new... (answered by london maths tutor)
The sum of the digits of a two digit counting number is 10. If the digits are reversed,... (answered by dabanfield)
The sum of the digits is 9. If the digits are reversed, the new number is 45 more than... (answered by longjonsilver)
The sum of e digits of a two digit number is 9. If the digits are reversed,the new number (answered by stanbon)
The sum of the digits of a two-digit number is 9. When the digits are reversed, the new... (answered by dfrazzetto)