You can put this solution on YOUR website! y=6x (red line)
y=3x-2 (green line (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, y = 6x and y = 3x -2 ).
y=x/2 (red line)
y=log2x (green line) (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions y = x/2 and y = log2x).
NOTE: IT APPEARS THIS GRAPHING SYSTEM CAN'T HANDLE LOGS.