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Linear equations word problems (advanced)

Problem

Sum of the digits of a two-digit number is 9.
When we interchange the digits, it is found that the resulting new number is greater than the original number by 45.
What is the two-digit number?
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
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