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Question 647180: I am thinking of a 2 digit number. The sum of the digits is 8. If I reverse the 2 digits then the value of the new number is 18 more than the orginal number. What is the orginal number?
-Do not understand, please help.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! I am thinking of a 2 digit number. The sum of the digits is 8. If I reverse the 2 digits then the value of the new number is 18 more than the orginal number. What is the orginal number?
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Let the number be 10t+u (t is the tens digit; u is the units digit)
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Equation:
t + u = 8
10u+t = 10t+u + 18
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Substitute for "t" and solve for "u":
10u + (8-u) = 10(8-u)+u + 18
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10u - 9(8-u) = u+18
10u -72+9u = u+18
18u = 90
u = 5 (that is the units digit)
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Solve for "t":
t = 8-u
t = 8-5
t = 3
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Original Number: 10t+u = 35
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Cheers,
Stan H.
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