Answer:
i dont get it
Step-by-step explanation:
Step-by-step explanation:

A.
If you multiply the original equation by 3 you get -45x+3y=54, which is the exact same as A, therefore they have infinite solutions.
We know that C is 385, so we can plug that in to get the equation 385=15n+85. To find the number of watches, we have to solve for n.
To do that we have to...
385=15n+85
First subtract both sides of the equal sign by 85 (because we need to do the opposite)
300=15n (because 85-85 is zero, so we eliminated that, and 385-85 is 300)
Now we divide both sides of the equal sign by 15 (again, opposites)
20=n (because 15n/15 leaves us with n since both 15s cancel out, and 300/15 is 20)
So the number of watches made were 20.
Use the midpoint formula,
(x1+x2/2,y1+y2/2)
(-1-5/2,1-3/2)
(-6/2,-2/2)
(-3,-1)