Answer: Slope = -3/4
slope = rise/run
rise = -3 ... move down 3 units
run = 4 .... move to the right 4 units
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Work Shown:
m = slope
m = rise/run
m = (change in y)/(change in x)
m = (y2-y1)/(x2-x1)
m = (-17-(-2))/(24-4)
m = (-17+2)/(24-4)
m = -15/20
m = -3/4 is the slope
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It basically means "move down 3 units, and move to the right 4 units"
So, slope = rise/run = -3/4
rise = -3 = move down 3 units
run = 4 = move to the right 4
You could express the slope as a decimal, and that would be -3/4 = -0.75, but you lose the rise and run values. So I recommend you keep the fraction.
Another problem with decimals is that sometimes we could have approximations that aren't exact. For example, if the slope was 2/3, then that approximates to 0.667 which may cause rounding errors down the line. Though I should point out that decimals do have their advantages in some cases.