Question

Find the two digit number whose tens digit is 4 less than its units digit if the original number is 2 more than 3 times the sum of the digits.

Answer 1

Use algebra.
Let A = the Tens digit
Let B = the Ones digit
The we have these two equations. A=B-4 given
and 10A + B = 3(A+B) + 2
Rearrange the two equations to look like:
A - B = -4 and
7A-2B = 2 Now solve using substitution or "elimination" method.