A)
145 - 5d
5d = 145, set equal
29 days to lay all the track
b)
5*19 = 95
145-95 = 50
After 19 days, they have 50 miles to go.
Answer:
Option C. 
Step-by-step explanation:
we know that
The volume of a cylinder is equal to

we have


substitute


no -17 is greater than -6
3: terms/ 12, 8r, -3, s, -5, 15t coefficients/ 8r, 1s, 15t