Question

I really need help with this. Can anyone help me?

1. The equation of the line that separates grasslands and
forests is 7P - 5T = -70

Write an inequality that describes temperatures and
amounts of precipitation that correspond to forested
regions. (Include the line.)

2. The equation of the line that separates grasslands and
deserts is 35P - 3T = 140

Write an inequality that describes temperatures and
amounts of precipitation that correspond to desert
regions. (Include the line.)

Answer 1

3. Using the information from Exercises 1 and 2, write a
system of inequalities that describes temperatures and
amounts of precipitation that correspond to grassland regions.

Answer 2

OK, I suppose everyone is put off by the P's and T's and whatnot.

Actually it's pretty straightforward.

You have 2 straight lines you can graph in the normal way except that you have P for x and T for y (say).

These 2 lines divide the plane in 3 (except that I am not too clear as to what happens "after" these two lines intersect (down in the 4th quadrant)).

Now all u have to do is read off the graph which values of P and T apply to the desert area in order to get your inequality (subject to an explanation of what happens where the lines intersect).