ECONOMICS

Algebraic Expressions and Equations

๐ŸŽฏ Lesson Objectives

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

  • Simplify algebraic expressions
  • Expand and factorize expressions
  • Solve linear and quadratic equations

๐Ÿ“– 1. Algebraic Expressions

An algebraic expression is a combination of variables, numbers, and operations.

Examples:

  • 4x+74x + 7
  • 3×2โˆ’5x+23x^2 – 5x + 2

๐Ÿ”น Simplifying Expressions

Combine like terms:

3x+2x=5x3x + 2x = 5x


๐Ÿ“– 2. Expanding Brackets

Use multiplication to remove brackets.

Example:

(x+3)(x+2)=x2+5x+6(x + 3)(x + 2) = x^2 + 5x + 6


๐Ÿ“– 3. Factorization

Factorization is the reverse of expansion.

Example:

x2+5x+6=(x+2)(x+3)x^2 + 5x + 6 = (x + 2)(x + 3)


๐Ÿ“– 4. Solving Linear Equations

A linear equation has the highest power of 1.

Example:

2x+6=142x + 6 = 14

Solve:

2x=8โ‡’x=42x = 8 \Rightarrow x = 4


๐Ÿ“– 5. Solving Quadratic Equations

A quadratic equation has the form:

ax2+bx+c=0ax^2 + bx + c = 0

๐Ÿ”น Method 1: Factorization

x2+5x+6=0โ‡’(x+2)(x+3)=0x^2 + 5x + 6 = 0 \Rightarrow (x + 2)(x + 3) = 0 x=โˆ’2orx=โˆ’3x = -2 \quad \text{or} \quad x = -3


๐Ÿ”น Method 2: Quadratic Formula

ย 
x=โˆ’bยฑb2โˆ’4ac2ax = \frac{-b \pm \sqrt{b^2 – 4ac}}{2a}
aa
bb
cc
-10-8-6-4-2246810-10102030-2.002.00

๐ŸŒ Real-Life Application

  • Calculating profit and loss
  • Determining distances and speeds
  • Solving everyday numerical problems

๐Ÿ“ Practice Exercises

  1. Simplify: 5x+3xโˆ’25x + 3x – 2
  2. Expand: (x+4)(xโˆ’1)(x + 4)(x – 1)
  3. Factorize: x2+7x+10x^2 + 7x + 10
  4. Solve: 3x+5=203x + 5 = 20
  5. Solve: x2+6x+8=0x^2 + 6x + 8 = 0

๐Ÿ’ก Lesson Summary

Students learned how to manipulate algebraic expressions and solve equations, which are essential skills for higher-level mathematics.



โœ… Lesson 2: Introduction to Functions and Graphs

๐ŸŽฏ Lesson Objectives

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

  • Understand what a function is
  • Evaluate simple functions
  • Identify basic types of functions
  • Draw and interpret simple graphs

๐Ÿ“– 1. What is a Function?

A function is a rule that assigns one output to each input.

Example:

f(x)=2x+3f(x) = 2x + 3

If x=2x = 2:

f(2)=7f(2) = 7


๐Ÿ“– 2. Linear Functions

Linear functions produce straight-line graphs.

ย 
y=mx+by = mx + b
mm
bb
-10-8-6-4-2246810-10-5510y-interceptx-intercept
  • mm = slope (steepness)
  • bb = y-intercept

๐Ÿ“– 3. Quadratic Functions

Quadratic functions form curved graphs (parabolas).

ย 
y=ax2+bx+cy = ax^2 + bx + c
aa
bb
cc
-10-8-6-4-224681020406080100120-4.23, 14.7

๐Ÿ“– 4. Drawing Graphs (Basic Steps)

  1. Choose values of xx
  2. Calculate yy
  3. Plot points
  4. Join points smoothly

๐Ÿ“– 5. Domain and Range (Basic Idea)

  • Domain โ†’ values of xx
  • Range โ†’ values of yy

๐ŸŒ Real-Life Application

  • Tracking business growth
  • Predicting population increase
  • Understanding motion in physics

๐Ÿ“ Practice Exercises

  1. Find f(4)f(4) if f(x)=3x+1f(x) = 3x + 1
  2. State whether this is linear or quadratic: y=x2+2y = x^2 + 2
  3. Draw a table for y=x+2y = x + 2 when x=0,1,2x = 0,1,2
  4. Identify slope and intercept in y=2x+5y = 2x + 5

๐Ÿ’ก Lesson Summary

Students learned how functions describe relationships between variables and how graphs help visualize

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