Question

The sum of the digits of a two-digit number is 12. If the units digit is 3 times the tens digit, find the number.

Answer 1

let a be the units digit and b be the tens digit
the number = 10b +a

to find a and b we must solve the system
a+b =12
a= 3b

can you solve it ??

Answer 2

I'm not understanding

Answer 3

you dont understand the part that the two digit number = 10b + a ??

Answer 4

I don't understand how we start at 10b+a and then we go to a+b=12

Answer 5

no! these two parts are not related directly..
10a+b is the general form of any two digits number

but a+b =12 is concluded from the given ( The sum of the digits of a two-digit number is 12)