Solving Linear Systems Using Substitution

The Lesson Activities will help you meet these educational goals:

·  STEM—You will analyze real-world situations.

·  21st Century Skills—You will apply creativity and innovation and use critical-thinking and problem-solving skills.

Directions

Save this document before beginning the lesson and keep the document open for reference during the lesson. Type your answers directly in this document for all activities.

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Self-Checked Activities

Read the instructions for the following activities and type in your responses. At the end of the lesson, click the link to open the Student Answer Sheet. Use the answers or sample responses to evaluate your own work.

Solving Linear Systems

a.  Sam wants to fence his rectangular garden plot along its length on the front side. The perimeter of the plot is 24 meters, and its length is 3 times its width.

·  If x is the length and y is the width of the plot, set the equations of the system.

·  Solve and determine the values of x and y.

·  If the cost of fencing is $25 per meter, how much does Sam need to spend on fencing?

Type your response here:

b.  A nutritionist recommends that John eat eggs and fish to meet his body’s protein and vitamin B requirements. Each ounce of egg contains 40 milligrams of protein and 20 milligrams of vitamin B. Each ounce of fish contains 50 milligrams of protein and 10 milligrams of vitamin B. John needs to reach a target of exactly 580 milligrams of protein and 200 milligrams of vitamin B.

·  If x and y represent the amounts of eggs and fish John needs to eat, set the equations of the system.

·  Express the simpler equation in terms of y.

·  How many ounces of eggs and fish should John eat?

Type your response here:

How did you do? Check a box below.

Nailed It!—I included all of the same ideas as the model response on the Student Answer Sheet.

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