Answer:
Step-by-step explanation:
Given:
L (d) = 207-7d
where:
L (d) = the length L (in miles), that is left to be paved after d days
d= number of days
To find the amount of miles of road that the crew have left to pave for 13 days, we plug in the given number of days into the equation:
L (d) = 207-7d
=207-7(13)
=116 miles
So, the crew have left 116 miles to pave for 13 days.
If 143 miles of road is left to be paved, the amount of days that the crew have been paving the road is:
L (d) = 207-7d
143 miles = 207-7d
Simplify and rearrange
7d=207-143
7d=64
d=64/7
d=9.14 days
Therefore, the crew have been paving for 9.14 days if 143 miles of road is left to be paved.