Please help me on this problem.
Complete the table so that I can plot the obtained quantities in a cartesian plane
It's really simple, all they are asking you to do, is to find y at the given x values, all you need to do is put x into the equation, and you'll get y.
So for the first part:
x = 2, y = -3
x = -6, y = 1
Plot these two points, join the dots and voila, you've got your first line!
For the second part:
x = 2, y = -5
x = 4, y = -7
Plot these two points, join the dots and voila, you've got your seoncd line!