The y axis for dependent variables and x axis for independent
For this case, the first thing we must do is define variables.
We have then:
x: number of cubic yards of mulch that first truck can transport
y: number of cubic yards of mulch that second truck can transport
Now we write the expression.
The first truck makes 12 trips to a job site:
The second makes 14 trips:
The difference between the first truck and the second truck is:
Answer:
An expression that represents the difference in the total number of cubic yards that the first truck delivers compared to the second is:
Locate 1 on the x axis. This is the horizontal number line.
Draw a vertical line through 1 on the x axis. Extend this vertical line as far up and down as you can.
Notice how the vertical line crosses the blue curve. Mark this point. Then draw a horizontal line from this point to the y axis. The horizontal line will touch -4 on the y axis. So that means the point (1,-4) is on the curve.
If the input it is x = 1, then the output is y = -4
So that's why the answer is choice A