Further preview of Sec Objective: solve a system of two linear inequalities in two variables and to Graph the solution sets.

Warm Up 1. Determine whether the point P is a solution of the linear inequality 2. Solve the linear system (use any method). 3x + 4y = 5 -2x + y = 4

Quick Review - What is the difference between an equation and an inequality? Which one is shaded? - When is the line solid? - When is the line dashed (dotted)? - How do you figure out where to shade? Graph this inequality: y > x – 2 m = 1 b = -2 Inequality ≤, ≥ Pick a point to plug in. =

Check if it’s a solution 1. (4, 10) 9x – y ≥ 23 5x + 0.2y ≥ (2, -1) y ≤ 4x + 1 y > -x + 2 Check (4, 10) 9x – y ≥ 235x + 0.2y ≥ 20 Check (2, -1) y ≤ 4x + 1y > -x + 2 YES 9(4) – 10 ≥ – 10 ≥ ≥ 23 5(4) + 0.2(10) ≥ ≥ ≥ ≤ 4(2) ≤ ≤ 9 -1 > -(2) > 0  NO

Graphing Systems of Linear Inequalities Graph each system 3. y x – 2 x ≥ -1 y ≤ - ½ x + 3

Graphing Systems of Linear Inequalities Graph each system 5. y > 2x – 5 6. y ≥ -x + 2 3x + 4y < 12 2x + 4y < 4

Writing Systems of Linear Inequalities Equation Write the inequalities for each system 7. 8.

Wrap Up Checking solutions – have to work for both equations Graphing Inequalities dashed (dotted) - solid - ≤ or ≥ shading – pick a point Writing equations of inequalities HW: P. 320 #19-23 odd, odd Write DLUQ for notes