Answer:
0
Step-by-step explanation:
Cancel out x-y to x^2-Y^2 and you get x+y-x-y which is 0
Line DQ is equal to 7. Since point Q is the centeriod, this means that line DQ will equal the same as line QD. Thus, line QD is 7 making like DQ 7 as well. Hope that helped :))