Sally's age is 3.
Tomas's age is 6.
x + 2y = 12
x - y = 3
Add y to both sides of the second equation.
x = 3 + y
Plug this equation into the first equation.
3 + y + 2y = 12
Combine like terms.
3 + 3y = 12
Subtract 3 from both sides.
3y = 9
Divide both sides by 3.
y = 3
Now that we have the value of y, we can find the exact value of x.
Plug this value into the second equation.
x - 3 = 3
Add 3 to both sides.
x = 6
We can verify by plugging these values into either equation.
6 + 2(3) = 12
6 + 6 = 12
12 = 12
The values are correct.