Please help lol.

Question

A state park charges $5 per car plus $1 per person as an admission fee. The total charged for a car with x people is f(x) = x + 5. How will the graph of this function change if the per car charge is changed to $8 per car?

A The line will shift vertically down by $3. 

BThe line will shift vertically up by $3.

C The line will shift vertically up by $8.

D The line will shift vertically down by $8.

Answer 1

This is another slope-intercept form question, y = mx + b where m = gradient of line, b = y intercept.

State park charges $5 per car + $1 per person is f(x) = x + 5. gradient is 1, y intercept is 5.

If car charge increases to $8, function changes to f(x) = x + 8. gradient is 1, y intercept is 8.

The y intercept moves up 3, answer (B).