I need some help please :)

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

Suppose that a households monthly water bill (in dollars) is a linear function of the amount of water the household uses (in hundreds of cubic feet, hcf). when graphed, the function gives a line with slope of 1.65. if the monthly cost for 13 hcf is $46.10 what is the monthly cost for 19 hcf?

Consider the following equation. 1/2x^3+x-7=-3sqrtx-1 approximate the solution to the equation using three iterations of successive approximation. use the graph below as a starting point. a. b. c. d.