Unit Resources

Unit: Systems of Equations and Inequalities
  
Essential Questions
EQ 1How can you solve systems of equations and inequalities?
EQ 2How can you use systems of equations and inequalities to model, and then solve, real-world problems?

Learning Objectives: Systems of Equations and Inequalities
6-1
    Solving Linear Systems by Graphing
  • Solve a system of linear equations by graphing
  • Model real-life problems using a linear system
6-2
    Solving Linear Systems by Substitution
  • Use substitution to solve a linear system
  • Model real-life situations using a linear system
6-3
    Solving Linear Systems by Linear Combinations (elimination)
  • Use linear combinations to solve a system of linear equations
  • Mode a real-life problem using a linear system
6-4
    Applications of Linear Systems
  • Choose the best method to solve a system of linear equations
  • Use a system to model real-life problems
6-5
    Linear Inequalities
  • graph linear inequalities in two variables
  • Model real-life problems using linear inequalities
6-6
    Solving Systems of Linear Inequalities
  • Solve a system of linear inequalities by graphing
  • Use a system of linear inequalities to model a real-life situation

Key Concepts
Systems Concepts:
  • consistent
  • inconsistent
  • dependent
  • independent
  • Linear inequalities, systems of linear inequalities
  • Solution of a linear equation
  • Solutions of a linear system
  • Solutions of a linear inequality
  • Solutions of a system of linear inequalities
Methods for solving systems:
  • graphing method
  • substitution method
  • elimination/linear combination method

Specific Skills Developed:
    You may expect a quiz on any of these skills
  • Determine whether a specified point is a solution to a system of equations
  • Solve a system of equations by graphing
  • Solve a system of equations using substitution
  • Solve a system of equations using elimination
  • Write a system of equations to model a word problem
  • Write a system of equations to model a word problem, solve the system, and verify the solution
  • Determine whether a specified point is a solution to an inequality
  • Determine whether a specified point is a solution to a system of linear equalities
  • Write a system of inequalities to model a word problem
  • Write a system of inequalities to model a word problem, solve the system, and verify the solution.

It is likely that a test will cover systems of equations, and that the assessment for systems of inequalities will be skills quizzes.

Content Covered
Text Book
Algebra I
  • Chapter 6 Systems of Equations and Inequalities

Homework Solutions
Texbook Solutions
Video Examples
Solutions to the Class Notes
6-2 Solving Systems Using Substitution

File:CW-6-2.pdf
You can download this file, review the sample problems, and try the practice problems. Then review the video solutions.
File:CW-6-2-Key.pdf has the answers, but not the solutions.
1)
x + y = 3
2x - y = 0
Video Solution
2)
x - 3y = -14
x - y = -2
Video Solution
3)
2x - 2y =10
x - y = 5
Video Solution not yet available
4)
4x + y = 8
x + 2y = 5
Video Solution not yet available
5)
-2x + y = 8
3x + y = -2
Video Solution not yet available
6)
3x - 4y = 8
2x + y = 9
Video Solution not yet available
7)
3x + 2y = 25
2x + 3y = -6
Video Solution not yet available
8)
6x - 5y = 3
x - 9y = 25
Video Solution not yet availableble
white board solution

This is an example from section 6-1, problem 15 solved using three methods - by graphing, by substitution, and by elimination. The elimination method is also sometimes call linear combinations.
Solve the system by graphing:
4x - y = -1
-x + y = x - 5
Video Solution
Solve the system by substitution:
4x - y = -1
-x + y = x - 5
Video Solution
Solve the system by Elimination:
4x - y = -1
-x + y = x - 5
Video Solution

Sample problems and worked out solutions from Ace100.org
You have $200 in your bank account and you are going to deposit $16 each week. Your sister’s bank account has $728 and she is going to withdraw $8 per week. In how many weeks will your accounts be equal?
Video Solution
Gabby has $5.65 in dimes and quarters. The number of dimes is 17 less than the number of quarters. How many coins of each type does she have?
Video Solution
The length of a rectangle is 16m less than 3 times the width. The perimeter is 128m. find the width, length, and area of the rectangle.
Video Solution
Ethan's age is 6 times Michelle's age. The sum of their ages is 21. Find the age of each.
Video Solution
The difference of Ethan's age and Bill's age is 13 . The sum of 6 times Ethan's age and 7 times Bill's age is 169. Find the age of each.
Video Solution
There were 304 people at a a fundraiser for the high school girls soccer team. Admission was $14 for each adult and $6 for each student. The total receipts for all ticket sales was $2,376.00. How many adult tickets and student tickets were sold?
Video Solution

Writing and Solving a System of Equations
  • Solve by Graphing Video on Educreations
    Five years from now, a father’s age will be three times his son’s age, and 5 years ago, he was seven times as old as his son was. What are their present ages?

Sample Skills
Online Practice
    Interactive Practice at Ace100.org . When you have Javascript enabled you can enter your answers, and/or get help prompts. Practice these problems until you can solve them using at least two methods.

    Tutorials
  • How to check if a point is a solution to a specified equation.
    Video on VirtualNerd.com
Sample Word Problems For each of these word problems, students should be able to:
  • Write a system of equations that models the propblem
  • Choose an appropriate method for solving the system - graphing, substitution, linear combinations
  • Solve the system (for all variables)
  • Check the solution (in all equations) algebraically

Samantha has $3.40 in dimes and quarters. The number of dimes is 8 less than the number of quarters. How many coins of each type does she have? A piggy bank has $4.30 in dimes and quarters. If the number of dimes is 7 more than 2 times the number of quarters, how many coins of each type are in the piggy bank?
George's age is 5 times Kendell's age. The sum of their ages is 48. Find the age of each. The difference of Jimmy's age and Linda's age is 10 years. The sum of 5 times Jimmy's age and 4 times Linda's age is 104. How old is each?
There were 235 people at a movie to raise funds for the drama club. Admision was $8.00 for each adult and $4.00 for each student. The total receipts for all tickets was $1504.00. How many adults and how many students attended? The length of a rectangle is 11 m less than 5 times the width. The perimeter is 434 m. Find the length and width of the rectangle.
George scored 13 more points than twice as many as Roy did. Their combined score was 40 points. How many points did each score? The difference of Jen's age and Mark's age is 6 years. The sum of 4 times Jen's age and 3 times Mark's age is 108. How old is each?

Previous Unit

Mini-Unit: Scatter Plots
  
Essential Questions
EQ 1What does the slope of a trend line indicate about the underlying data?

Learning Objectives, Skills and textbook Correlations
5-7
    Scatter Plots and Trend Lines
  • Write an equation of trend line and line of best fit from data in a scatter plot.
  • Make a scatter plot and describe its correlation
  • Determine whether a linear model is appropriate
      Fitting a Line to Data
    • Find a linear equation that approximates a set of data points
    • Determine whether there is a positive or negative correlation, or no correlation, in a set of real-life data points.

Key Concepts
Scatter Plot Concepts:
  • causal relationship
  • correlation
  • coefficient,
  • extrapolation
  • interpolation
  • line of
  • best fit
  • negative correlation
  • no correlation
  • positive correlation
  • trend line
Content Covered
Text Book
Algebra I
  • Chapter 5 Writing Linear Equations
    5-7 Scatter Plots and trend Lines

Online Resouces

  • Homework answer key HW-5-7-Key.pdf problems 7 - 29, with more details for the even problems 20-28. This is a pdf of the answers reviewed in class.

Summary and Reminders
    Summary
  • Slope-Intercept form of an equation: y = mx + b
  • Point-Slope intercept form of an equation: y - y1 = m(x - x1)
  • Standard form of an equation: Ax + By = C
  • Parallel lines have the same slope
  • Perpendicular lines have oppostite reciprocal slopes

    Reminders
  • Main things you will be quizzed/tested/assessed on include being able to create a scatter plot from a table of data; identify from a scatter plot whether there seems to be a positive correlation, negative correlation, or no correlation.

  • Over time, with more practice you will be able to interpret the correlation correficient and make judgements as to whether a linear model is appropriate for a group of data.

Next Unit: Skills Quizzes : Systems of Equations

Quiz Name Skill Assessed Practice File Passing Grade Notes
Graphing Solve systems of equations by graphing; check the solution See homework assignments for practice problems 3 out of 4
Substitution Solve systems of equations using the substitution method; check the solution. See homework assignments for practice problems 3 out of 4  
Linear Combinations Solve systems of equations using linear combinations; this includes adding, subtracting, multiplication, division; check the solution. See homework assignments for practice problems 3 out of 4  
Writing Systems of Equations Write a system of equations to model a problem; then solve the system and check the solution. 5 out of 6
Writing Systems of Equations Write a system of equations to model a problem; then solve the system and check the solution.
Sample: The difference of George's age and Madison's age is 9 years. The sum of 6 times George's age and 5 times Madison's age is 153. How old is each?
Practice problem sets (PDF) 3 out of 3 Practice problem set solutions (PDF)

Prior Units

Unit 5 Linear Equations
Mini-Unit Scatter Plots