Answer:
-2/3 will be your answer
Explanation:
I always like putting standard from into y=mx+b as you can just easily see the slope. 
2x + 3y = 10
subtract 2x from each side
3y = -2x + 10 
now to single out the 'y' divide by 3 on each side
y = -2/3 + 10/3
Hence, option A is your answer!
Hope this helps :>