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## Two Equations, Two Unknowns - I

Summary

Understanding and solving systems of equations with two variables are fundamental skills in algebra, offering a basis for more complex mathematical concepts.

- A single equation with two variables typically has an infinite number of solutions, which, when plotted on an x-y graph, lie on a straight line.
- A system of equations involves two equations with two variables that must be satisfied simultaneously, usually resulting in a unique solution where the lines intersect.
- There are two primary methods for solving systems of equations: substitution and elimination, with substitution being ideal when one of the variables has a coefficient of plus or minus 1.
- The substitution method involves solving one equation for one variable and then substituting that expression into the other equation to solve for the second variable.
- Elimination method, which will be covered in the next lesson, is preferred when substitution is not convenient, typically due to the presence of fractions.

Chapters

00:00

Introduction to Systems of Equations

02:56

Solving Systems of Equations: The Big Ideas

03:48

Substitution Method Explained