The <u>rise</u> is the difference in y-coordinates:
The <u>run</u> is the difference in x-coordinates:
The <u>slope</u> is the quotient of rise over run:
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If two points on a line are A(10, −3) and B(12, 9), the rise is <u>12</u>, and the run is <u>2</u>, so the slope of the line is <u>6</u>.
Exponential.
One way to think about this, is to ask how much you will lose each year. The first year you're losing 20% of $20,000 ($4,000). The second year you're losing 20% of 16,000 ($3,200). The dollar value your car loses each year diminishes exponentially, so it is not a linear but an exponential function.
(0, 4) and (2, 0) are the coordinates
