The units digit is 3 times the tens digit. The number is 12 more than the tens digit

Question

part 2

The units digit exceeds the tens digit by 6. The number is 10 more than 9 times the tens digit.

Answer 1

The Tens digit is T

the units digit is U

U = 3T <--- units digit is 3 times the tens digit

10T+U = T+12 <--- the actual number is 10T + U and it is 12 more than the tens digit

10T + 3T = T + 12 <--- substitution

13T = T + 12

12T = 12

T = 1

So the units digit is 3, which makes the number 13. Note that 13-12 = 1 which is the tens digit

================================================================

U = T+6

10T + U = 9T + 10

10T +T+6 = 9t + 10

11T + 6 = 9t + 10

2T + 6 = 10

2T = 4

T=2

so the units digit is 8, which makes the number 28.

Note that 28 = 9*2+10 which is 10 more than 9 times the ten's digit