MathIsimple

Systems of Linear Equations

Solve linear systems using Gaussian elimination, understand rank and solution classification, and interpret Ax = b as linear combinations. Master systematic methods for solving systems of any size.

12th Grade
Linear Algebra
~90 min
🎮 Interactive Activity: Gaussian Elimination Solver

Solve the system of linear equations!

System of Equations:

2x + 3y = 7
1x + 4y = 9
🎮 Interactive Activity: Solution Type Classifier

Classify the solution type of the system!

System:

2x + 3y = 1
4x + 5y = 6
1. Gaussian Elimination Method

The Gaussian Elimination Process

Gaussian elimination uses elementary row operations to transform an augmented matrix [A|b] into row-echelon form, making it easy to solve the system by back substitution.

Example 1: Basic 2×2 System

System: 2x + 3y = 7, x + 4y = 9

Step 1: Augmented matrix: [[2, 3 | 7], [1, 4 | 9]]

Step 2: Row operations to get: [[1, 0 | 1], [0, 1 | 2]]

Answer: x = 1, y = 2

Example 2: 3×3 System

System: x + y + z = 6, 2x - y + z = 3, x + 2y - z = 0

Step 1: Create augmented matrix

Step 2: Apply row operations to achieve row-echelon form

Step 3: Back substitute to find: x = 1, y = 2, z = 3

Answer: x = 1, y = 2, z = 3

Example 3: Reduced Row-Echelon Form (RREF)

Goal: Transform to [[1, 0, 0 | a], [0, 1, 0 | b], [0, 0, 1 | c]]

Advantage: Solutions can be read directly from RREF

Method: Continue row operations until pivots are 1 with zeros above and below

2. Elementary Row Operations
3. Rank and Solution Classification
4. Linear Combination Interpretation
5. Solution Types and Parametric Forms
6. Real-World Applications
7. Advanced Topics: Pivots and Free Variables
Frequently Asked Questions

Practice Time!

Practice Quiz
10
Questions
0
Correct
0%
Score
1
What is the solution to the system: 2x + 3y = 7, x + 4y = 9?
2
For a system Ax = b, when does it have a unique solution?
3
What does it mean if rank(A) < rank([A|b])?
4
In Gaussian elimination, what is the purpose of row operations?
5
If a system has 3 equations and 3 unknowns, and rank(A) = 2, how many solutions?
6
What is a pivot in row-echelon form?
7
For the system x + y = 3, 2x + 2y = 6, what is the solution type?
8
What does it mean if Ax = b is interpreted as a linear combination?
9
In a 3×3 system, if rank(A) = 3 and rank([A|b]) = 3, what is the solution?
10
What is reduced row-echelon form (RREF)?