Seven points more than twice the number of the points scored by the other team write an expression

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

Write the equation in logarithmic form m^x=n

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.