Which equation represents a proportional relationship?

A. y=−x

B. y = 5x + 1

C. y=
1
5x

D. y=−5(x+1)

If you could answer these your a life saver

The length of the line segment joining the midpoints of sides ab and bc of the parallelogram abcd is 10. find the length of diagnol ac

Jayne is studying urban planning and finds that her town is decreasing in population by 3% each year. the population of her town is changing by a constant rate.true or false?