A construction crew is lengthening a road. The road started with a length of

56
miles, and the crew is adding
3
miles to the road each day.
Let
L
represent the total length of the road (in miles), and let
D
represent the number of days the crew has worked. Write an equation relating
L
to
D
. Then use this equation to find the total length of the road after the crew has worked
39
days.

L=56+3D

To write an equation relating L to D, we know that the road started with a length of 56 miles, and the crew is adding 3 miles to the road each day. Since the crew has worked for D days, the total length of the road after D days can be calculated as:

L = 56 + 3D

To find the total length of the road after the crew has worked 39 days, we can substitute D = 39 into the equation:

L = 56 + 3(39)
L = 56 + 117
L = 173

Therefore, the total length of the road after 39 days of work by the crew is 173 miles.

To find the equation relating L to D, we can start with the given information: the road started with a length of 56 miles, and the crew is adding 3 miles each day.

Let's break down the information into variables:
L - total length of the road
D - number of days the crew has worked

Since the crew is adding 3 miles to the road each day, the increase in length can be represented as 3D (3 miles * D days).

Starting with a length of 56 miles and adding 3D, we can write the equation as:
L = 56 + 3D

Now, we can use this equation to find the total length of the road after the crew has worked 39 days. Plugging in D = 39 into the equation, we get:
L = 56 + 3(39)
L = 56 + 117
L = 173

Therefore, the total length of the road after the crew has worked 39 days is 173 miles.