Key learning points

1. Additively combining the equations does not eliminate one variable unless the coefficients are the same.
2. Equivalent equations should be formed so the coefficients of one variable are the same (if not already).
3. When considering the coefficients, use your knowledge of LCM to help.

Common misconception

Keywords

• Simultaneous equations - Equations which represent different relationships between the same variables are called simultaneous equations.

• Elimination - Elimination is a technique to help solve equations simultaneously and is where one of the variables in a problem is removed.