ANSWER:
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EXPLANATION:
This equation is called a slope intercept form. The formula is y=mx+b.
"b" or -4 in this case is the y-intercept. It's where the line meets the y line (vertical line). The "m" or 2/3 is the slope. All slopes are written in y/x.
So, starting from (0, -4), you will go up 2 and go right 3. You will end up at (3, -2). Now, just draw a line through (0, -4) and (3, -2).
Your graph should show up like this:
635,500. Because 21,700 grows every year.
$2.56 * 15 gallons = $38.4 (total)
2 person split = $38.4 / 2 = $19.2/person
another friend = +1
$38.4 / 3 = $12.8
each person saves = $19.2 - $12.8 = $6.4/person
i hope this helps :)