Solve Systems of Linear Equations: Substitution and Elimination Methods

Published on April 9, 2026

Algebra

Learn to solve systems of linear equations using both substitution and elimination methods. This guide provides step-by-step solutions for two example systems.

Question

Answer

Let’s solve the first system of equations.
The given system of equations is:
We can use the substitution method or the elimination method. Let’s use the elimination method.
Multiply equation (1) by 4 to make the coefficients of opposites:
Now, add equation (2) and equation (3):
Divide by 63 to solve for :
Now substitute the value of into equation (1):
Add 28 to both sides:
Multiply by -1 to solve for :
So, the solution to the first system is and .
Now let’s solve the second system of equations.
The given system of equations is:
We can use the substitution method or the elimination method. Let’s use the elimination method.
Multiply equation (2) by 5 to make the coefficients of opposites:
Now, add equation (1) and equation (3):
Divide by 55 to solve for :
Now substitute the value of into equation (2):
Add 20 to both sides:
So, the solution to the second system is and .
The final answer is for the first system and for the second system.