Answer:
D(-1,-8)
Step-by-step explanation:
See attached graph.
Plot the given points, then find the equation that links A and C and a second one to link C and B. Plot those lines (Black and Red). Find 2 equations for lines parallel (same slope, m) to these two lines. Adjust the value of the y-intercept, b, such that one line intersects point A and the other point D (the Green and Blue lines). Where those lines intersect will be the point D.
D (-1,-8)
