Answer:
I can't see the fine details of the image displaying the weights of the bags but I would assume the heaviest bag is 2(3/4) pounds, being Bag C. The lightest bag is most likely Bag B, being 2(3/8) pounds.
18,560 - 15,787 = 2,773
2773/18560 x 100 = 14.94 which is rounded up to about 15%
Triangles are congruent
so
4x + 1 = 13
4x = 12
x = 3
In case you need to find y
2x + y = 8x - 2y
2(3) + y = 8(3) - 2y
6 + y = 24 - 2y
3y = 18
y = 6