Answer:
Step-by-step explanation:
We can start as expressing the number as 10x+y, where x is the 10's digit and y is the 1's digit. From here, you can set up the following equations:
10x+y=3y+6
x+y=9
You can subtract x from both sides of the second equation, and substitute the y value into the upper equation like so:
10x+(9-x)=3(9-x)+6
10x+9-x=27-3x+6
Combining like terms:
12x=24
x=2
y=7
The number is 27.
Hope this helps!