Answer: 3/2 cm per second
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Explanation:
We could compute the slope of this line to get the answer, or we could simply compute y/x. This shortcut only works because the line goes through the origin. If the line didn't go through the origin, then we would have to use the slope formula.
The unit rate is y/x = 9/6 = 3/2 cm per second. I used the point (9,6) to compute the unit rate.
We can think of the fraction 3/2 as 1.5, so the unit rate is equivalent to 1.5 cm/sec.
