Answer: Choice B
65/1; Your car travels 65 miles in one hour (aka 65 miles per hour)
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t = time in hours
D = distance in miles
r = rate or speed in miles per hour
the formula is D = r*t which can be solved for r to get r = D/t. You divide both sides by t to get this new formula.
Based on that formula, we'll divide each distance (second column) over its corresponding time (first column). We divide the values only that are in the same row.
Row1: D/t = 260/4 = 65
Row2: D/t = 390/6 = 65
Row3: D/t = 520/8 = 65
Row4: D/t = 650/10 =65
We get the same result each time
An alternative way to get the answer is to use the slope formula. I'm going to use the values found in the first two rows of the table.
m = (y2-y1)/(x2-x1)
m = (390-260)/(6-4)
m = (130)/(2) <<-- this means we travel 130 miles in 2 hrs
m = 65 <<--- which is equivalent to 65 miles in 1 hr
The slope of the line is 65, which is the rate of change 65/1
slope = rise/run = 65/1
rise = 65, run = 1
rise = 65 means we increase 65 miles and run = 1 indicates that 1 hour has gone by. Visually we move up 65 each time we move to the right 1.
