Niki scored a 78 on her first test and an 85 on her second. niki forgot what she got on her third test bit she knows that her average is an 85. what did she score on her third test? write and sole an equation for this problem.

What is the volume of this square pyramid?

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?

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?