help with elimination/substitution important!!! Urgent.

The sum of the digits of a two-digit number is 9. If the number is doubled, then decreased by 36, the answer is the original number with the digits reversed. Find the answer.

You have to solve this word problem using elimination. Please help.

Any Ideas?

you don't need an equation

This kind of question is very difficult to put in equation form. but if the 2-digit number is 't,s' where t is the tens digit and s is the ones digit then:

t+s=9

2(10t+s) - 36 = 10s + t

however you stated in your problem that you must use elimination.

With elimination we do not use equations we logically look at all possibilities and eliminate.

In this case 18, 27, 36, 45, 54, 63, 72, 81, and 90 are the only possible two digit numbers whos digits sum to 9.

Now you can look at them individually to see if they satisfy the second rule and __eliminate__ those which do not.