Solve Two Equations In Two Variables Algebraically Lesson Plan for 9th Grade Example Students

Topic: Solve two equations in two variables algebraically

Objectives & Outcomes

• To be able to solve two equations in two variables algebraically.

Materials

• Pen and paper for each student
• Two equations in two variables (one with x and one with y)

Warm-up

• Write down two equations in two variables on the board, one with x and one with y.
• Ask students what they notice about the two equations.
• Ask students if they can solve the two equations.

Direct Instruction

• Explain that we can solve two equations in two variables algebraically by first adding or subtracting the two equations to get a single equation in one variable.
• For example, if we have the equations x + y = 6 and y - x = 3, we can add the two equations to get x + y + y - x = 6 + 3 = 9, which simplifies to x = 9 - y.
• Next, we can use the resulting single equation in one variable to solve for the other variable.
• In the example, we can solve for y by dividing both sides by 9 and getting y = 1/9.
• Finally, we can use the single equation in one variable to solve for the second variable using the original equations.
• In the example, we can use the equation x = 9 - y to solve for x by subtracting y from both sides and getting x = 9 - 1/9 = 8/9.

Guided Practice

• Give students a set of equations to solve algebraically, such as x + y = 6 and y - x = 3.
• Have them work in pairs to solve the equations and check their work against the solutions provided in the solutions section.
• As a class, go over the solutions to make sure everyone understands how to solve the equations.

Independent Practice

• Have students solve a variety of equations in pairs, such as x + y = 6 and y - x = 3, as well as more complex equations such as x - y = 10 and 2x + y = 18.
• Encourage them to use their pencils and paper to solve the equations, but allow them to use a calculator if needed.
• As a class, go over the solutions to make sure everyone understands how to solve the equations.

Closure

• Ask students to share one thing they learned during the lesson.
• Summarize the key concepts of solving equations in pairs and encourage students to continue practicing.

Assessment

• Observe students during the guided and independent practice to assess their understanding of solving two equations in two variables algebraically.
• Collect and grade the solutions to the puzzle and the written explanations as a formative assessment.
• Give a quiz at a later date to assess students' retention of the concepts learned in the lesson.