Find the real or imaginary solutions. x^4+3x^2-18=0 SHOW WORK

How do i work this problem out using the equation a=pe^rt

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?

What is the inverse of the function f(x) = 2x + 1?