Question 116309
The tens' digit of a two-digit number is on more than the units' digit. If the number is divided by the sum of the digits, the quotient is equal to seven. What is the number? 
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Let the number be 10t+u where t is the ten digit and u is the unit digit.
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EQUATIONS:
t = u + 1.
(10t+u)/(t+u) = 7
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Substitue and solve for "u":
(10(u+1)+u)/(u+1+u) = 7
(11u+10)/(2u+1) = 7
11u+10 = 14u+7
3u = 3
u = 1
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Substitute to solve for "t":
t = u+1 = 2
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The number is 21
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Cheers,
Stan H.