Consider the equation
1) First row of the table
Set x=0 and solve as follows:
The answer is y=20 and the pair x-y is (0,20)
2) Second row
Set x=1 and solve, as follows:
The answers are y=10 and (1,10)
3) Third row.
Set y=0 and solve as follows:
The answers are x=2 and (2,0)
If x is the number of berries you can buy with 1 dollar,
1 pound of blueberries = $4.00
x pound of berries = $1.00
Lets set up a proportion- because these are directly proportional- when there is more pounds of berries, it will cost more.
Cross multiply
4x=1
Divide both sides by 4 to isolate x
x=1/4 or $0.25