Need help on this math equation 6c^2-5d+8 when c=5 and d=4

What is the ratio for the surface areas of the cones shown below, given that they are similar and that the ratio of their radil and altitudes is 4: 3? 23

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?

What would be the reasons for lines 3 and 4? a. addition property; subtraction property b. addition property; solve c. substitution property; subtraction property d. substitution property; prove