Today’s Objective
•To be able to solve a system of linear inequalities by graphing.
Graph y < 2x - 1 Sketch y = 2x - 1
y= 2x - 1
Now pick a point on one side of the dotted line (-1,0)
Test a Point
• Take the point (-1,0) and plug in the values in y < 2x - 1
•y < 2x - 1 •0 < 2(-1) -1 •0 < -3
since it’s False, shade the opposite side of (-1,0).
Graph y < 2x - 1
y= 2x - 1
Solve by Graphing
•y < x + 2 •y > -1/2x + 5
Graph y < x + 2 Graph y = x + 2
Now pick a point on one side of the dotted line (0,0)
Solve by Graphing
• Substitute (0,0) in for x and y
•y < x + 2 •0 < 0 + 2 •0 < 2
Graph y < x + 2 Graph y = x + 2
Graph y > -1/2x + 5 Graph y = -1/2x + 5
Now pick a point on one side of the dotted line (0,0)
Solve by Graphing
• Substitute (0,0) in for x and y
•y > -1/2x + 5 •0 > -1/2(0) + 5 •0 > 5
Graph y > -1/2x + 5 Graph y = -1/2x + 5
Graph y < x + 2 Graph y > -1/2x + 5
Graph y < x + 2 Graph y > -1/2x + 5