Answer:
13
Step-by-step explanation:
a + b = 6 and a - b = 4
Add the two equations together
a + b = 6
a - b = 4
----------------
2a = 10
Subtract the two equations
a + b = 6
- a + b = -4
----------------
2b = 2
b =1
Multiply by 3
3b =3
2a +3b
we know 2a = 10 and 3b = 3
10+3
13
