Solution: The commutative property of addition states that when two numbers are being added, their order can be changed without affecting the sum.
I think the answer is 80 degrees. Think about it like you're moving the chunk with 100 degrees already filled in, to the space where you're trying to find the amount since they're the same. Vertical angles are supplementary and are equal to 180. So, 100+x = 180. x would equal 80 degrees.
18 - 7x = -20.5
Subtract 18 from each side:
-7x = -38.5
Divide both sides by -7:
x = -38.5 / -7
x = -5.5 = 5 1/2
The answer is D.
Where are the functions?
your question is incomplete?