How do you differentiate

Which equation represents a proportional relationship that has a constant of proportionality equal to 1/5

The expression 6x2 gives the surface area of a cube, and the expression x3 gives the volume of a cube, where x is the length of one side of the cube. find the surface area and the volume of a cube with a side length of 6m

If you had $1,900,000, how many days would it take you to spend all if you spent $1 a second. (there are 86,400 seconds in a day)