Question

A BMW car on a truck weighs 20 tons plus 1 ton per cubic yard of x cubic yards of spares that it carries. The total weight of a truck with BMW is: f(x) = x + 20. How will the graph of this function change if the BMW weight is changed to 15 tons? The line will shift vertically up by 5 tons. The line will shift vertically up 15 tons. The line will shift vertically down by 5 tons. The line will shift vertically down by 15 tons.

Answer 1

Using f(x) = x +20 the y -intercept = 20

 changing the weight to 15
 
makes the equation f(x) = x +15 , making the y intercept 15

 which moves the line vertically down by 5 ( 20-15=5)

The line will shift vertically down by 5 tons.

Answer 2

The answer to your question would be The line will shift vertically down by 5 tons.