Question

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

Answer 1

unit digit ---- x
tens digit ---- x+5

x + x+5 = 9

carry on, should be able to do it mentally.

Answer 2

x+ x + 5 = 9
9 - 5 = 4
there are two x's
4 / 2 = 2
x = 2
units digit = 2
2 + 5 = 7
tens digit = 7
number = 72

Answer 3

x+ x + 5 = 9
9 - 5 = 4
there are two x's
4 / 2 = 2
x = 2
units digit = 2
2 + 5 = 7
tens digit = 7
number = 72