Ican t figure this one ! steven recorded the growth of a plant over 10 wk for his

The answer is y = 1.2x + 2

x - the number of weeks
The equation is:    y = ax + b

He started the project when the plant was 2 in.
x = 0  (at the beginning, there were 0 weeks)
y = 2
y = ax + b
2 = a * 0 + b
2 = 0 + b
b = 2

At week 5, the plant was 8 in. 
x = 5
y = 8
b = 2

y = ax + b
8 = a * 5 + 2
8 = 5a + 2
8 - 2 = 5a
6 = 5a
a = 6/5 = 12/10 = 1.2

The equation is:
y = 1.2x + 2

The concentration difference is the difference of concentration in the blood when entering the lungs, increasing the difference increases the rate of diffusion. Diffusion difference is the distance between the respiratory membrane, increasing the distance causes a decrease in diffusion rate. The surface area of the lungs affects the available space for diffusion, decreasing the surface area decreases the diffusion rate

Explanation: