Answer:
(-1;-2).
Explanation:
if the point A has coordinates (-1;-8), the point B has (-1;7) and the point C is required point, then
1) the 'x' coordinates of the points A and B is '-1', therefore the 'x' coordinate of the point C is '-1', ;
2) the 'y' coordinate of the point C is:
3) finally, the point C has coordinates (-1;-2).