Question 1072305
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A number of two digits is such that twice the tens digit is 8 less than seven times the unit digit. 
When the digits are reversed, the number is decreased by 9. What is the number? 
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Let the number be 10t+u
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Equations:
2t = 7u-8
10t+u - 10u+t = 9
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Rearrange:
2t - 7u = -8
9t - 9u = 9
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2t - 7u = -8
2t - 2u =  2
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Subtract and solve for "u":
5u = 10
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u = 2.


Then t = 3.


The number is 32.


Solved.