In a factory there are three machines, a, b, and c. when all three machines are working, they produce 287 bolts per hour. when only machines a and c are working, they produce 197 bolts per hour. when only machines a and b are working, they produce 202 bolts per hour. how many bolts can machine b produce per hour?

85 bolts.

Step-by-step explanation:

The work rate of a machine is given by the job completed per time:

. If your problem has multiple machines working together to complete a job, you should sum their work rates:

In the problem given:

To solve the equation system for , you could subtract the first and last equations:

Then, .

answer:

c. the third graph