Is 3√8 rational or irrational

What is another way to express 36 +32

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 following sum in simplest form? square root 8 + 3 square root 2 + square root 32