Answer:
14
Step-by-step explanation:
1. Do the "Two Mark" Rule
- 7 + (+12) - 5
2. Do your addition before subtracting
- 7 + 12 = 19
3. Subtract your remaining two numbers
- 19 - 5 = 14
We can put the two equations together with substitution, and we get
3x + 2y = 30
Now we have a single equation in two variables, so we don't have enough information to solve for both x and y.