Answer:
Pat a) The unit rate of graph at left is ![25\ \frac{grams}{cup}](https://tex.z-dn.net/?f=25%5C%20%5Cfrac%7Bgrams%7D%7Bcup%7D)
Part b) The unit rate of graph at right is ![40\ \frac{grams}{cup}](https://tex.z-dn.net/?f=40%5C%20%5Cfrac%7Bgrams%7D%7Bcup%7D)
see the attached figure
Step-by-step explanation:
we know that
The unit rate of a linear equation is the same that the slope of the linear equation
step 1
Find the slope of the graph at left
This graph represent a proportional relationship (because the line passes through the origin)
The slope is equal to the constant of proportionality k
![k=\frac{y}{x}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7By%7D%7Bx%7D%20)
we have the point (1,25)
substitute the values in the formula
![k=\frac{25}{1}=25\ \frac{grams}{cup}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B25%7D%7B1%7D%3D25%5C%20%5Cfrac%7Bgrams%7D%7Bcup%7D)
step 2
Find the slope of the graph at right
we have the points (2,80) and (3,120)
This graph represent a proportional relationship (because the line passes through the origin)
The slope is equal to the constant of proportionality k
![k=\frac{y}{x}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7By%7D%7Bx%7D%20)
Is necessary only one point to determine the constant of proportionality
take the point (2,80)
substitute the values
![k=\frac{80}{2}=40\ \frac{grams}{cup}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B80%7D%7B2%7D%3D40%5C%20%5Cfrac%7Bgrams%7D%7Bcup%7D)
<u>Verify</u>
The formula to calculate the slope between two points is equal to
![m=\frac{y2-y1}{x2-x1}](https://tex.z-dn.net/?f=m%3D%5Cfrac%7By2-y1%7D%7Bx2-x1%7D)
we have the points (2,80) and (3,120)
substitute the values
![m=\frac{120-80}{3-2}](https://tex.z-dn.net/?f=m%3D%5Cfrac%7B120-80%7D%7B3-2%7D)
![m=\frac{140}{1}=40\ \frac{grams}{cup}](https://tex.z-dn.net/?f=m%3D%5Cfrac%7B140%7D%7B1%7D%3D40%5C%20%5Cfrac%7Bgrams%7D%7Bcup%7D)