10. What value of x and y will make the polygon a
parallelogram?

Answer:
Step-by-step explanation:
20 = 5y
4=y
x+3y = 2(x+y-1)
x+3y = 2x +2y -2
x+3(4) = 2x + 2(4) -2
x +12 = 2x +8 -2
12-8+2 = 2x -x
6 =x