you could say if you knew how many cubes there were in total, you could subtract them
-40/80 = -1/2
since when you’re multiplying fraction, you multiply the top by the top number and bottom by the bottom number. So -4 • 10 is -40 and 5 • 16 is 80. -40/80, simplified is -1/2.
The answer to your question is b

has y = 0 as a solution.
Selection B is appropriate.