Question 917699
Let T be the digit for the tens place and let U be the digit in the ones place.
The two-digit number is 10T+U.
In this expression for the number, T and U are both DIGITS and NUMBERS.


The "second" digit means the variable U and the "first" digit is the variable, T.


The description about them means, {{{U=2+5T}}}; and {{{5T=3+U}}}.
Those are a system of two equations in two unknown variable.
You may still be struggling to know what to do with these equations but your
daughter probably does know what to do with them to solve for T and U.
SIMPLE HINT:  Substitution.