Now that we have practiced graphing one inequality at a time, let's practice graphing a system of 2 linear inequalities...
Steps for Solving a System of Inequalities Graphically:
1. Get
alone in both inequalities. You must flip the inequality symbol if you multiply or divide by
a
number.
2. Identify the
>
(m) and
(b) for both.
3. Graph the lines as dotted or solid. (see table to the right)
4. Shade upward (
) or downward
) for each. The double shaded region is
your SOLUTION SET. Label the solution set with a large "S”.
5. Choose a point in the double shaded region and make sure (x, y) makes BOTH inequalities TRUE.
Example 3:
a) Solve by graphing. Label the solution set with an "S".
A.
2x + y > 5
B.
3x - y22
b) Is (3,1) a solution to this system?
c) Is (0,-2) a solution to this system?
d) Is (3,-1) a solution to this system?