Substitution Method Calculator

Solve systems of linear equations using the substitution method with step-by-step solutions

System of Linear Equations

First Equation: a₁x + b₁y = c₁

0 = 0

Second Equation: a₂x + b₂y = c₂

0 = 0

Example Problems

Example 1: Simple System

System:

3x - 4y = 6

-x + 4y = 2

Solution: x = 4, y = 1.5

Example 2: No Solution

System:

2x + 3y = 7

2x + 3y = 10

Solution: No solution (inconsistent)

Substitution Method Steps

1

Choose equation

Select one equation to solve for a variable

2

Solve for variable

Express one variable in terms of the other

3

Substitute

Replace the variable in the other equation

4

Solve & verify

Find values and check by substitution

Solution Tips

Choose the equation with coefficient ±1 for easier algebra

If both variables disappear and you get 0 = 0, there are infinite solutions

If both variables disappear and you get 0 = non-zero, there's no solution

Always verify your solution in both original equations

Understanding the Substitution Method

What is the Substitution Method?

The substitution method is a technique for solving systems of linear equations by solving one equation for one variable and then substituting that expression into the other equation. This reduces the system to a single equation with one unknown.

When to Use Substitution

  • When one variable has a coefficient of ±1
  • When one equation is already solved for a variable
  • When dealing with non-linear systems
  • For educational purposes to understand solution methods

Types of Solutions

Unique Solution

System has exactly one solution (x, y) that satisfies both equations.

Infinite Solutions

Both equations represent the same line (dependent system).

No Solution

Equations represent parallel lines (inconsistent system).

General Form

a₁x + b₁y = c₁

a₂x + b₂y = c₂

where a₁, b₁, c₁, a₂, b₂, c₂ are constants