SOLUTION: When graphing a linear inequality, how do you know if the inequality represents the area above or below the line and when is the line itself included or not included in the solutio

Algebra ->  Graphs -> SOLUTION: When graphing a linear inequality, how do you know if the inequality represents the area above or below the line and when is the line itself included or not included in the solutio      Log On


   

Question 29624: When graphing a linear inequality, how do you know if the inequality represents the area above or below the line and when is the line itself included or not included in the solution?
Answer by Cintchr(481) About Me  (Show Source):
You can put this solution on YOUR website!
When working open and closed half planes (shaded sections), chose a point NOT on the line. I like using (0,0). plug it into the equation. For Example ...
3x+%2B+4y+%3C=+12
if we use (0,0) we get
3%280%29+%2B+4%280%29+%3C=+12
0+%2B+0+%3C=+12
0+%3C=+12
this is a true statement so we shade the side of the line that (0,0) is on.
If it is a false statement ... shade the other side.