Answer:
A linear graph is nothing but a straight line or straight graph which is drawn on a plane connecting the points on x and y coordinates.
The formula of a slope:

We have the points A(-6, 6) and B(12, 3). Substitute:

Therefore we have
.
Put the coordinates of the point B to the equation:

<em>add 2 to both sides</em>

Answer:

I'm assuming you're trying to find out how much you'll spend annually on gas: first you would divide the total miles driven in a year (13,000) by your car's mpg (26) giving you a quotient of 500 (the amount of times you'll have to fill up your tank) from here you will need to multiply 500 times the cost of gas ($3.60) giving you a product of $1,800 spent on gas annually.
Rule for 1 is the rule for 1 is 14 times 3.5^x and it is exponential
The second one is is also exponential and the rule is 32 times .25^x and the last one is is linear and the rule is 5x+-4