Input data
$20 for all day pass
$ 10 for pass after 5pm
Wednesday park = $1000
Equation
1000 = 20x + 10y
Procedure
a) Find the x-intercept
Intercept with x occurs when y = 0

The intercept with the x-axis means that only all-day passes are sold.
b) Find the y-intercept
Intercept with y occurs when x = 0

The y-axis intercept means that only passes are sold after 5pm.
c) graph