ABCD is a parallelogram. Solve for BC.
B
X + 8
с
A
2x +1 D
BC =

Step-by-step explanation:
BC = AD (opposite sides in parallelogram is equal)
x + 8 = 2x + 1
8 - 1 = 2x - x
7 = x
x = 7
BC = x + 8 = 7 + 8 = 15