Algebra math.
posted by Lucy on .
1) the sum of the digits of a two digit number is 9. The value of the number is 12 times the tens digit. Find the number.
2) the sum of the digits of a two digit number is 12. If 15 is added to the number the result is 6times the units digit. Find the number.
Please help!!
Thanks (:

let the unit digit by x
let the tens digit be y
so x+y=9, both x and y being whole numbers
value of number = 10y+x
given: 10y+x = 12y
or x = 2y
back in the first:
x+y=9
2y+y=9
y=3, and thus x = 6
the number is 36
let's see you do the second question in the same way. 
Thanks ! This really helped (: