Скачать или смотреть Solving systems of equations

*CORE CONCEPT:*
Solving systems of equations involves finding values for variables that satisfy multiple linear equations simultaneously, typically using substitution or elimination methods.

*TOPICS COVERED:*
When to use substitution to isolate one variable (B1)
How to substitute an isolated variable into another equation (B1)
When to find the solution point (x, y) that satisfies both equations (B1)

*EXAMPLE SENTENCES:*
Example 1: y = 2x, x + y = 9.
Example 2: x + y = 10, y = 3x - 4.
Example 3: 2x + y = 8, y = x - 2.

*GRAMMAR RULES:*
Step 1 → Choose one equation → Solve for one variable (x or y).
Step 2 → Substitute expression from Step 1 → Into the other equation.
Step 3 → Solve resulting equation → Back-substitute to find both variables.

*COMMON ERRORS:*
Wrong: Not isolating a variable correctly → Right: Isolate one variable correctly.
Wrong: Incorrect substitution → Right: Substitute into the other equation properly.
Wrong: Failing to simplify correctly → Right: Always simplify equations properly.

*STUDENT QUESTIONS:*
How do I isolate a variable in a linear equation?
When do I substitute a variable in a system of equations?
Is my substitution method correct in this example?
What's the difference between solving by substitution and elimination?
How do I find the solution point for two equations?

*KEY CONCEPTS:*
Systems of equations, substitution method, linear equations, B1 level, solving for variables.