Question

The price of dress fabric is proportional to the length of fabric purchased. The graph shows this relationship.

Answer 1

C. $8/1 m
the y axis (going up) is price.the x axis (going to the left) is the length.
the 1st point is the unit rate. 1 meter is $8, 2 meters is $16. 3 meters is $24...and so on.
the unit rate wont work with all graphs this is a lucky problem. reading this graph is still the same tho. 

Answer 2

C. 8$/m. The rate is the same as the slope. To find the slope, we find "rise over run," or the change in the height/change in length (OR, change y/ change x) 
The change in y is 24-8=16
The change in x is 3-1=2

16/2= 8$/1 m.   This is the unit rate because it describes the change in y over ONE UNIT of x.