As discussed in Locating Points in Quadrants and on Axes,
an ordered pair
$\,(x,y)\,$ is a pair of numbers,
separated by a comma, and enclosed in parentheses.
The number that is listed first is called the first coordinate or the
$\,{x}$value.
The number that is listed second is called the second coordinate or the
$\,y$value.
The coordinate plane
(also called the $\,xy$plane)
is a device to ‘picture’ ordered pairs.
Each ordered pair corresponds to a point in the coordinate plane,
and each point in the coordinate plane corresponds to an ordered pair.
For this reason, ordered pairs are often called points.
Recall that the origin is the point $\,(0,0)\,$.
This section gives you practice with the connection between ordered pairs and movement in the coordinate plane.
Left/right movement is controlled by the $\,x$value (the first coordinate).
Moving to the right increases the $\,x$value; moving to the left decreases it.
For example, if a point $\,(a,b)\,$ is moved two units to the right,
then the new coordinates are $\,(a+2,b)\,$.
If a point $\,(a,b)\,$ is moved three units to the left,
then the new coordinates are $\,(a3,b)\,$.
Up/down movement is controlled by the $\,y$value (the second coordinate).
Moving up increases the $\,y$value; moving down decreases it.
For example, if a point $\,(a,b)\,$ is moved four units up,
then the new coordinates are $\,(a,b+4)\,$.
If a point $\,(a,b)\,$ is moved five units down,
then the new coordinates are $\,(a,b5)\,$.
Recall that the origin is the point $\,(0,0)\,$.
Suppose you have a line drawn on a piece of paper.
On this same piece of paper, you have a point.
For the moment, suppose that the point does not lie on the line.
To ‘reflect the point about the line’ means, roughly,
that you want the point that is the same distance from the line,
but on the other side of the line.
This idea is illustrated below:
reflecting about an arbitrary line:
the distance from P to Q is the same as the distance from P' to Q. (the coordinates of the reflected point are not so easy to find) 
reflecting about the $\,x$axis (the $x$value stays the same; take the opposite of the $\,y$value) 
reflecting about the $\,y$axis (the $y$value stays the same; take the opposite of the $\,x$value) 
Notice that if you fold the piece of paper along the line of reflection,
then the original point and its reflection will land right on top of each other.
It's kind of like reflecting in a mirror
—except instead of the mirror reflecting
‘back at you’,
it instead projects to the other side.
If a point actually lies on the line that you're reflecting about,
then the reflection of the point is itself.
$(2,5)$ 
original point: currently $\,5\,$ units from the $\,x$axis (above) and $\,2\,$ units from the $\,y$axis (to the left) 
$(2,5\cdot 2) = (2,10)$  double distance from $\,x$axis; stay above 
$(2\cdot 3,10) = (6,10)$  triple distance from $\,y$axis, stay to the left 
CONCEPT QUESTIONS EXERCISE:
On this exercise, you will not key in your answer.However, you can check to see if your answer is correct. 
PROBLEM TYPES:
