Solve for X please :)

What is the solution of sqrt x+2-15=-3

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?

If f(x) = 2x + 8 and g(x) = x4, what is (gº)?