I hope this helps you
5=7x+0.1+10x-0.2
17x=5.1
x=5.1/17
x=3/10
x=0.3
You can find the area of a triangular prism by putting it into a bet and finding the area of all sides then adding them together
1. Turn improper


2. set up the problem

now multiple across and simplefy
It descended 240 feet 12*20 is 240