Systems of Equations

How to work through it

1. Substitution works best when one equation is already solved for a variable.
2. Elimination: align like terms and add/subtract whole equations.
3. Check ordered pair solutions in BOTH original equations.
4. Word problems: define two variables and write two equations.
5. Draw lines for each equation if elimination feels unclear.

You should be able to

• ·Solve systems by graphing and interpret the intersection.
• ·Solve systems by substitution.
• ·Solve systems by elimination.
• ·Model real situations with systems of two equations.

Key words

System of equations

Two or more equations considered together.

Solution of a system

The point (x, y) that satisfies every equation.

Substitution

Replacing a variable with an equivalent expression to solve.

Elimination

Adding or subtracting equations to remove a variable.

Extra practice links