About 400 zebras live at the game reserve.
The proportion would be
30/150 = 80/x
This is because 30 zebras are tagged out of 150 in one area. We know that they tagged 80 total zebras out of x total zebras.
To solve this, cross multiply:
x*30 = 150*80
30x = 12000
Divide both sides by 30:
30x/30 = 12000/30
x = 400
Y= -1/2x+2 since the y-intercept is 2 and the slope is going down by 1/2, you can find the equation using the y=mx+b form