Answer:
52.
Step-by-step explanation:
b÷2=10 and a-b=12
You work it backwards; dividing becomes multiplying, subtracting becomes adding, multiplying becomes dividing, and adding becomes subtracting.
With that, multiply both sides of the first problem (b÷2=10) by 2, then you have b=20.
Plug b into the second equation (a-b=12) then solve.
a-20=12
Add 20
a=32
Because it is asking for the value of a+b, add 20 and 32 and you get 52.