Answer:
1: It places them in an order sequentially relative to each other.
2: Number lines show the location of a number relative to each other on a one dimensional plane, and a coordinate plane does the same on two axis, or a two dimensional plane.
3: The order of the numbers do matter because the first one is the x coordinate and the second is the y. We nee a point of reference so we aren't able to make it so a single point can be represented by multiple ordered pairs, and vice versa so we can accurately share the information without additional interpretation.
4: (4.75, 2.25) Because to move across the x axis is to move in a direction perpendicular to it, meaning only the y coordinate will change. To be mirrored, it has to be copied and the absolute value of y (from both the x and y axis) must be maintained, just moved into the quadrant above or below it.
5: It is 7 units because the original coordinate would be 3.5 (as explained previously), and to move all the way to -3.5 you would need to cover the first 3.5 units to get to y=0, and then another 3.5 units down to get to y=-3.5. This is a total of 7 units moved.
Explanation: