Unit 3 Review Answers

3.4: Systems of Inequalities

Objectives:

• Sketch graphs of inequalities in two variables.
• Solve systems of inequalities.

Example 1

Student Example 1

Example 2

Student Example 2

Problem Set 3.4:

#10, 12, 28, 36, 46, 71

3.3b: Multivariable Linear Systems

Objectives:

• Solve systems that are inconsistent or have infinitely many solutions.
• Solve non-square systems.

Example 1

Student Example 1

Example 2

Student Example 2

Example 3

Problem Set 3.3b:

#20, 22, 26, 28, 51

3.3a: Multivariable Linear Systems

Objectives:

• Solve systems using back substitution.
• Solve systems using Gaussian Elimination.

Gaussian Elimination Dot Diagram

Example 1

3.3a problem set:

#2, 4, 6, 13, 16, 18

3.2: Two Variable Linear Systems

Objectives:

• Solve linear systems by elimination.
• Classify linear systems.

Example 1

Student Example 1

Example 2

Student Example 2

Example 3
*Error: row speed = 5mph, current speed = 3 
(I made a mistake in solving the system)

Student Example 3

Problem set 3.2

#12, 18, 19, 20, 43, 49, 51, 53

3.1b: Linear and Non-linear Systems of Equations

Objectives:

• Given a word problem, set up and solve a linear or non-linear system of equations.

Example 1

Example 2

Student Example 1

Problem set 3.1b:

64, 65, 67, 68

3.1a: Systems of Equations

Objectives:

• Solve systems by graphing.
• Solve systems algebraically.

Example 1

Example 2

Student Example 1

Problem Set 3.1a:

#2, 6, 8, 16, 26, 44, 48