SOLUTION: The sum of the digits of certain two digit number is 7. Reversing its digits increases the number by 9. What is the number? And what is its linear equation?

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Question 429763: The sum of the digits of certain two digit number is 7. Reversing its digits increases the number by 9. What is the number? And what is its linear equation?
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
Let t=the tens digit and u=the units digit.
10t+u is the number.
10t+u=10u+t-9
9t-9u=-9
.
t-u=-1 divide each side by 9
t+u=7
-------add
2t=6
.
t=3
u=4
.
Ed