The tens digit of a two-digit number is five more than the units digit. The sum of the digits is 9. Find the number.

72

Step-by-step explanation:

7-2=5 which fits the requirement.

7+2 = 9 which also works so its 72

B=A+5

10A+B=3 (A+B)

Replace the B's in the bottom equation with A+5s, because we know that's the same thing from the top equation

10A+A+5=3 (A+A+5)

11A+5=3 (2A+5)

11A+5=6A+15

5A=10

A=2

Then B is 5 more than that so B=7

Your number is 27

**To double check**

When we double check this and see 7 is 5 more than then 2. Then 27 is three times what we get when we add the digits (2+7=9).