AlgèbreFacile

Math Learning Platform

Simple Equations - Level 1

Intermediate

📚 equations

📖 About this lesson

Solve your first degree equations

Lesson Content

First Degree Equations

What is an equation?

An equation is an ,[object Object], with an unknown (often x).

📝 Example

Example: x + 5 = 12

Fundamental principle

We can perform the ,[object Object], on both sides of the equality without changing it.

Solving simple equations

Type: x + a = b

Subtract a from both sides.

[object Object],: x + 7 = 15

x + 7 - 7 = 15 - 7
x = 8

[object Object],: 8 + 7 = 15 ✓

Type: x - a = b

Add a to both sides.

[object Object],: x - 3 = 10

x - 3 + 3 = 10 + 3
x = 13

Type: a × x = b

Divide by a on both sides.

[object Object],: 4x = 20

4x / 4 = 20 / 4
x = 5

Type: x / a = b

💡 Tip

Multiply by a on both sides.

[object Object],: x3 = 6

x3 × 3 = 6 × 3
x = 18

Equations with multiple operations

[object Object],: Isolate x step by step

[object Object],: 2x + 5 = 13

Subtract 5: 2x = 13 - 5 = 8
Divide by 2: x = 8 / 2 = 4

[object Object],: 2×4 + 5 = 8 + 5 = 13 ✓

Equations with x on both sides

[object Object],: 5x + 3 = 2x + 12

Subtract 2x: 3x + 3 = 12
Subtract 3: 3x = 9
Divide by 3: x = 3

Always verify!

Replace x with the found value in the initial equation.

Practical Examples

Example 1

📋 Problem

Résoudre : x + 8 = 15

✅ Solution

x = 7

💡 Explanation

x = 15 - 8 = 7. Vérification : 7 + 8 = 15 ✓

Example 2

📋 Problem

Résoudre : 3x = 21

✅ Solution

x = 7

💡 Explanation

x = 21 / 3 = 7. Vérification : 3 × 7 = 21 ✓

Example 3

📋 Problem

Résoudre : 2x - 4 = 10

✅ Solution

x = 7

💡 Explanation

2x = 10 + 4 = 14, puis x = 14 / 2 = 7

Ready to Practice? 💪

5 exercise(s) available for this lesson

Test your knowledge and earn points!

🎯 Leçon Suivante Suggérée

Systèmes d'Équations

avance

Suite logique

Résolvez des systèmes d'équations linéaires avec plusieurs méthodes