Answer:
k = 7/3
Explanation:
Let's first find the equation of line AC. Since point A has an x-coordinate of 0, we know that point A is the y-intercept so when writing the equation of AC in slope-intercept form, we know that b = -2 in y = mx + b (Note that m = slope and b = y-intercept). To find m, we can use points A and C, therefore, m = (0 - (-2)) / (-2 - 0) = 2 / -2 = -1. Now, we know that the equation of line AC is y = -x - 2. To solve for k, we know that point B belongs to AC and that x = -k, y = 5 - 2k in point B, therefore, after plugging those values into y = -x - 2, we get:
5 - 2k = -(-k) - 2
5 - 2k = k - 2
5 - 3k = -2
-3k = -7
k = 7/3