Mathematics - Senior Secondary 1 - Simple equation and variations

Simple equation and variations

 

TERM: 1ST TERM

WEEK: 12
Class: Senior Secondary School 1
Age: 15 years
Duration: 40 minutes of 5 periods
Subject: Mathematics
Topic: Simple Equation and Variations
Focus: Revision of Simultaneous Linear Equations in Two Unknowns, Types and Applications of Variations

 

SPECIFIC OBJECTIVES:

By the end of the lesson, students should be able to:

  1. Revise and solve simultaneous linear equations in two unknowns.
  2. Understand the types of variations (direct, inverse, joint, and combined variations).
  3. Apply variations to real-life problems.
  4. Solve word problems involving all types of variations.

 

INSTRUCTIONAL TECHNIQUES:

  • Question and answer
    • Guided demonstration
    • Discussion
    • Practice exercises
    • Real-life application of variations

 

INSTRUCTIONAL MATERIALS:

  • Whiteboard and markers
    • Charts on types of variations
    • Flashcards with examples of simultaneous equations and variations
    • Worksheets for solving equations and problems on variations

 

PERIOD 1 & 2: Revision of Simultaneous Linear Equations in Two Unknowns

PRESENTATION:

Step

Teacher’s Activity

Student’s Activity

Step 1 - Introduction

Revises the concept of simultaneous linear equations in two unknowns using examples (e.g., x + y = 10, x - y = 2).

Students listen and recall methods of solving simultaneous equations.

Step 2 - Solving Methods

Demonstrates solving using substitution and elimination methods.

Students observe, take notes, and ask questions for clarity.

Step 3 - Example 1

Solves a problem: 2x + 3y = 7 and x - y = 1. Demonstrates the steps using substitution: solving for x or y first.

Students follow along, taking notes.

Step 4 - Example 2

Solves another problem: 3x - y = 5 and 2x + y = 6 using the elimination method (add the equations to eliminate y).

Students observe and practice in pairs.

NOTE ON BOARD:
Simultaneous Equations:

  • Substitution Method: Solve one equation for one variable, substitute in the other.
  • Elimination Method: Add or subtract equations to eliminate one variable.

 

EVALUATION (5 exercises):

  1. Solve 2x + 4y = 12 and x - 2y = 1.
  2. Solve 3x - 2y = 4 and 4x + y = 10.
  3. Solve 5x + y = 15 and 2x - 3y = -4.
  4. Solve 6x + 3y = 18 and 2x + y = 7.
  5. Solve 7x - 3y = 11 and 3x + y = 5.

CLASSWORK (5 questions):

  1. Solve 4x + 2y = 10 and x + 3y = 7.
  2. Solve 5x - y = 8 and x + 4y = 9.
  3. Solve 3x + y = 7 and 2x - 2y = 4.
  4. Solve 6x - 3y = 9 and 2x + y = 5.
  5. Solve 3x + 2y = 10 and x - y = 4.

ASSIGNMENT (5 tasks):

  1. Solve 4x - 3y = 5 and 5x + y = 11.
  2. Solve 7x + y = 9 and 2x - y = 3.
  3. Solve 5x + 3y = 15 and 2x + y = 7.
  4. Solve 3x + y = 7 and 2x + y = 5.
  5. Apply simultaneous equations to solve a real-life problem (e.g., cost of two items when given total costs for different quantities).

PERIOD 3 & 4: Types and Application of Variations

PRESENTATION:

Step

Teacher’s Activity

Student’s Activity

Step 1 - Introduction to Variations

Introduces the concept of variations: direct, inverse, joint, and combined.

Students listen attentively and ask questions.

Step 2 - Direct Variation

Explains direct variation (y = kx) with an example (e.g., y = 3x). Discusses how y increases as x increases.

Students observe, take notes, and discuss real-life examples.

Step 3 - Inverse Variation

Explains inverse variation (y = k/x) with an example (e.g., y = 12/x). Discusses how y decreases as x increases.

Students take notes and relate examples to real-life situations.

Step 4 - Joint and Combined Variation

Introduces joint variation (y = kxz) and combined variation (y = kx/z). Provides examples of combined and joint variations in practical scenarios.

Students observe and practice with examples in pairs.

NOTE ON BOARD:
Types of Variation:

  • Direct Variation (y = kx): y increases as x increases.
  • Inverse Variation (y = k/x): y decreases as x increases.
  • Joint Variation (y = kxz): y varies with the product of x and z.
  • Combined Variation (y = kx/z): y varies with x and inversely with z.

 

EVALUATION (5 exercises):

  1. If y = 6x, find y when x = 4.
  2. If y = 12/x, find y when x = 3.
  3. If y = kxz, find k if x = 2, z = 3, and y = 24.
  4. If y = kx/z, find y when x = 8, z = 4, and k = 5.
  5. Solve a real-life problem involving direct variation (e.g., speed and distance).

CLASSWORK (5 questions):

  1. If y = 5x, find y when x = 6.
  2. If y = 10/x, find y when x = 5.
  3. If y = kxz, find k when x = 1, z = 4, and y = 12.
  4. If y = kx/z, find y when x = 10, z = 2, and k = 3.
  5. Solve a word problem involving inverse variation (e.g., pressure and volume).

ASSIGNMENT (5 tasks):

  1. Solve a real-life problem involving joint variation (e.g., area of a triangle with base and height).
  2. Solve a word problem involving combined variation (e.g., the relationship between speed, time, and distance).
  3. If y = 2x, find y when x = 7.
  4. If y = 15/x, find y when x = 5.
  5. Apply variations to solve a practical problem (e.g., how temperature affects the volume of a gas).

 

PERIOD 5: Solving Problems Involving All Types of Variations

PRESENTATION:

Step

Teacher’s Activity

Student’s Activity

Step 1 - Problem-Solving Techniques

Guides students in solving word problems involving all types of variations (direct, inverse, joint, and combined).

Students listen and ask questions about solving practical problems.

Step 2 - Example Problem 1

Provides an example of a word problem involving direct and inverse variation: "If the amount of time taken to fill a tank is directly proportional to the size of the tank and inversely proportional to the speed of water, how long will it take to fill a 5-liter tank at a speed of 2 liters per hour?"

Students observe the solution and discuss the method.

Step 3 - Example Problem 2

Provides a combined variation example: "The area of a rectangle is directly proportional to the length and inversely proportional to the width. If the area is 24 cm² when the length is 6 cm and the width is 4 cm, what is the area when the length is 8 cm and the width is 3 cm?"

Students follow the solution process and solve similar problems.

NOTE ON BOARD:

  • Direct and Inverse Variation Problems: Use y = kx and y = k/x.
  • Joint and Combined Variation Problems: Use y = kxz and y = kx/z.

 

EVALUATION (5 exercises):

  1. Solve a word problem involving direct variation.
  2. Solve a word problem involving inverse variation.
  3. Solve a word problem involving joint variation.
  4. Solve a word problem involving combined variation.
  5. Solve a mixed variation problem with all types of variation.

CLASSWORK (5 questions):

  1. Solve a real-life problem involving direct variation (e.g., salary and hours worked).
  2. Solve a real-life problem involving inverse variation (e.g., pressure and volume of gas).
  3. Solve a word problem involving combined variation (e.g., speed, distance, and time).
  4. Solve a problem involving joint variation (e.g., area of a triangle).
  5. Solve a mixed variation problem using all four types of variation.

ASSIGNMENT (5 tasks):

  1. Solve a word problem involving direct variation.
  2. Solve a word problem involving inverse variation.
  3. Solve a word problem involving joint variation.
  4. Solve a combined variation problem.

Apply variations to solve a practical real-life problem.