What Are Systems of Equations?

Systems involve two or more equations working together. The solution is where all equations are true at the same time.

Solving Methods

• Substitution: Replace one variable with an expression from the other equation.
• Elimination: Add or subtract equations to eliminate a variable.
• Graphing: Find the point where the lines cross.

Applications

• Figuring out prices when you know totals and quantities.
• Finding where two moving objects meet.

SAT Tips

• Label your variables.
• Watch for clues in the question about which method to use.

Real-World Example

Balancing your spending (money in vs. money out) or mixing two recipes to get a certain flavor.