What does it mean to have one peak on a chromatograph

You could get more than one peak for several reasons.

One could be that the sample is not pure and it is in fact that the different compounds that give rise to the different peaks. This depends on what kind of detector you have. It could be many different types of contamination (from septum, solvent, sample preparation etc).

It could be that there is something wrong with your injection valve so that splits the sample into parts somehow and give rise to multiple peaks.

It could be isomers of the same compound, even though this is usually not something you separate "by accident". But for some compounds it is possible.

There is also possible that your analyte is degrading or reacting with something else in the solvent or sample preparation step. This will also give rise to extra peaks (If you use a less specific detecor like UV).

Explanation:

because it says use -2,0,and 2 for x, we can plug those numbers into the equation. y/4=3/4(-2)+2   y/4= -1 1/2 +2 now to get x by itself, we can multiply each side by 4. y=-6+8 which equals y=2 when x=-2. now you can do the same thing with 0 and 2 as x. you get y=8 when x=0 and y=14 when x=2.

x   |   y

-2 |   2

0   |   8

2   |   14