SOLUTION: The units digit of a two-digit number is 1 less than 3 times the tens digit. if the digits are reversed , the new number is 45 more than the original number. find the number .

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: The units digit of a two-digit number is 1 less than 3 times the tens digit. if the digits are reversed , the new number is 45 more than the original number. find the number .       Log On


   

Question 853708: The units digit of a two-digit number is 1 less than 3 times the tens digit. if the digits are reversed , the new number is 45 more than the original number. find the number .
what i have so far
U= 3X-1 (u being unit , x being tens)
10x+ U = 10u+x -45
plugged everything and answer came out decimals. which isn't on the answer sheet lol . i probably did some wrong math somewhere down the line. help me out . Thx
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
"IF THE DIGITS ARE REVERSED".... This means, 10%2AU%2B1%2AX.

Forty five more than the original number: 10U%2BX=45%2B%2810X%2BU%29.


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Also, stay with one case level or the other. Do not mix them for the same expression or the same number. M%3C%3Em; D%3C%3Ed,...
... otherwise, your first two steps seem good so far. I think your second step was going off-track.

U=3X-1 and 10U%2BX=45%2B10X%2BU;
10U-U%2BX-10X=45
9U-9X=45
9%28U-X%29=5%2A9
U-X=5
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Substitute using the U equation ...
%283X-1%29-X=5
3X-X-1=5
2X-1=5
2X=6
X=3----------result
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U=3%2A3-1
U=9-1
U=8----------result
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ORIGINAL NUMBER = 83.