Answer:
D
Step-by-step explanation:
The correct answer is, obviously, 34/7.
Step-by-step explanation:
and
are linear pair angles.

D-10-2d+7 = 8 + d- 10 -3d
d-2d-10+7 = 8-10 +d -3d
-d-3=-2-2d
-d+2d=3-2
d=1
Final answer: C. d=1
3,857:
1. 3 is located in the thousands place
2. Since 8 is bigger than 3, it's telling it to go up a number (turning 3 into a 4)
Stays the Same: 1,2,3,4
Goes Up: 5,6,7,8, etc.
So 3,857 is now rounded into 4,000