First, we must find the slope-intercept form of the line. In y = mx + b form, the slope-intercept equation would be y = 2x - 8. At this point, we can plug in 0 for y in the equation and evaluate for k. This gives us the answer of k = 4. Next, we have to show that P is the midpoint of AB. In order to do so, we can use the midpoint equation to find that the midpoint of AB is (4,0). Therefore, we have proved that AP = BP.
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