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.
By using the given pairs e.g (4,1 ) (8,6) on the graph plane
Answer:
Step-by-step explanation:
First you do the parentheses so the -3 x 8n= -24 and -3 x -5= 15
so it will look like this. -24n+15-2n=8n-21
Now combine like terms the -24n-2n.
-26n+15=8n-21 now subtract 8n now it will look like this
-34n+15=-21 now -15 from -21
-34n=-36
now if you want n by its self divide -34 and -36
ANSWER:
b) No
c) Yes
EXPLANATION:

b)
3 (-8 + 1) = 3 x -8 + 3
(3 x -8) (3 x +1) = 3 x -8 + 3 (just put left and right sides into calcu separately)
-72 = -21
Both sides are not equal and therefore it isn't a solution.
c)
3 (0.5 + 1) = 3 x 0.5 + 3
(3 x 0.5) (3 x +1) = 3 x 0.5 + 3
4.5 = 4.5
Both sides are equal and thereofre it IS a solution.
5 squared is 5x5. And 2 cubed is 2x2x2. So, the answer would be 200.