If the positions of the single digit and the ten digit of a two digit number are exchanged, the new two digit number will be 9 larger than the original two digit number. How many two digit numbers are there? What are their characteristics?

If the positions of the single digit and the ten digit of a two digit number are exchanged, the new two digit number will be 9 larger than the original two digit number. How many two digit numbers are there? What are their characteristics?

Let the original two digits be 10A + B, according to the meaning of the question: 10A + B + 9 = 10B + 1, the solution is: B = a + 1, because it can take 1 to 8 numbers, so the two digits have 8, they are respectively, 12, 23, 34, 45, 56, 67, 78, 89, they are two digits whose one digit is bigger than ten digits

1, a two digit number, the sum of its two numbers is 11, and the new number obtained by transposing the single digit number of the two digits with the ten digit number is 63 larger than the original number. Let the single digit number of the original two digits be x, and the ten digit number be y. then the algebraic expression of the original two digits is (). According to the meaning of the question, we get the equations ({), and solve the equations ({), then the two digit number is ()

10y+x；10x+y=10y+x+63,x+y=11；x=9,y=2；29