Answer:
D.

Explanation:
We are given that
Cost of roller coaster ride= 4 tickets
Cost of boat ride=3 tickets
Michael went on the two rides a total =10
Total spend on two rides =37 tickets
Let r be the times of coaster ride and cost of coaster ride= 4 tickets
Therefore, total cost of coaster ride =4r
Number of times of boat ride =10-r
Cost of boat ride =3 tickets
Total cost of boat ride=3(10-r)
Total spent on two rides=4r+3(10-r)

This is true equation.
Option D is true.