Answer:
It would be 14.2+-5a
Explanation:
It would be that because first, u have to add all the numbers with the same variable ad 8 and 4a don't have the same variable, and as you can see the addition sign on 6.2 and they have the same variable so it would be 14.2. Then you would have to find the value of s so 4.2 u wouldn't add it with 9a even though it has the same variable you have to subtract because it has a subtraction sign above it so since 4a came first u subtract 9a from 4a which would give u -5a.