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.

Question

hoblos · Answer

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 ??

anonymous · Answer

I'm not understanding

hoblos · Answer

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

anonymous · Answer

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

hoblos · Answer

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)

anonymous · Answer

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