The slope formula is (y2-y1)/(x2-x1).

So for this graph I chose these points: (-1-3)/(2-0) this would give you -4/2 which means that the slope is -2. It is negative because the y value is decreasing as you move left to right (as the x value increases).

This line is linear because if I put different numbers in the slope formula the slope stays the same. For example, (-3-5)/(3-(-1)) which would give you -8/4 which is still -2. Therefor the line is linear.Â

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