When a mathematician writes QED at the end of a proof, what does this mean? A. The proof cannot be completed.

B. The proof needs more reasons.

C. The proof is done.

D. The proof is too long

step-by-step explanation:

i believe it is c.y = 9x

rise over run. 9 units up over 1 unit right or 9/1

step-by-step explanation :

we know that

the measurement of the outer angle is the semi-difference of the arcs which comprises

in this problem

m< xzy is the outer angle

substitute the values

the measure of angle xoy is equal to

> by central angle

substitute the value

i believe that the answer is

b. y-1=-2(x-4)

hope this !