You can put this solution on YOUR website!
.
.
.
Plot the line
.
.
.
.
.
.
Now choose a test point in either plane, not on the line.
(,) is a good choice.
Test the inequality.
If the inequality is satisfied, shade the region containing (,).
If not, shade the other region.
False, shade the region not containing (,)
.
.
.