Need quick algebra help?

You don't say if you have been told to use a suggested range of values of x, so on the assumption that you haven't, we're going to use values from -4 to + 4 for x. Set it out as below (but I warn you that "Answers" takes great pleasure in totally destroying any attempt at laying out a table!)

x| -4 -3 -2 -1 0 1 2 3 4

x^2| 16 9 4 1 0 1 4 9 16 (these numbers should be immediately below those

2x| -8 -6 -4 -2 0 2 4 6 8 above - now add these two rows

y | 8 3 0 -1 0 3 8 15 24

The top row of the table and the bottom row (labelled y) you take together as x and y coordinates: (-4,8), (-3,3), (-2,0), (-1, -1) etc. Plot these points, and draw a smooth curve through them.