Simplify 6z + 9 + 3z + 2

The parabola opens: y=√x-4 (principal square root) up down right left

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?

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?