For the first one is has greater then 3 terms
The middle one is has exactly one term
And the last one is has two terms
I believe I hope this helps
You need to set up a linear graph. One side with gallons and the other with dollars. Point 1 will be at (1500, 2.10). Point 2 (1300, 2.95). Draw a straight line through these points in your graph and your graph will then give you the answers to your other questions.
Pythagoras theorem I guess
500=4πr^2. first divide 500 from four which will equal 125, then divide 125 with π and it will equal 39.788 . finally √39.788. the answer will be r=6.3 or 6
The answer is one in a half