Start by multiplying the 9 out:
9(-6 + 8y) = -54 + 72y
Then, add the 7:
-54 + 72y + 7
Then simplify the whole thing:
-47 + 72y
Step-by-step explanation:
The number of people to paint the bridge is inversely proportional to the number of hours it takes.
(If there are more people, it will take less time etc.)
9 people can paint the bridge in 5 hours.
=> 2 people can paint the bridge in 5 * (9/2) = 22.5 hours.
