Answer:
33.
Step-by-step explanation:
8x + 4y = 44
4(2x + y) = 44
2x + y = 44/4 = 11.
6x + 3y
= 3(2x + y)
= 3 * 11
= 33.
The fraction is 36/42.
36 + 42 = 78
36/42 = 6/7
If you mean proof that the opposite sides of a parallelogram are equal, you draw a diagonal then prove that the 2 triangles formed are congruent.