Mathematics for IGCSE & O level - Equations (Section 5 - No. 24)
Identify the step(s) required to eliminate a variable when solving a system of equations.
Add the equations directly, if coefficients are opposite.
Subtract one equation from another, if coefficients are the same.
Multiply one or both equations by a constant to make coefficients the same or opposites.
Isolate a variable in one equation and substitute.
Explicación
All strategies are ways to eliminate a variable.