Mathematics for IGCSE & O level - Equations (Section 6 - No. 28)
What is a typical first step in solving a system of equations using substitution?
Adding the two equations together.
Isolating a variable in one of the equations.
Multiplying both equations by a constant.
Setting both equations equal to each other.
Shpjegimi
Isolating a variable makes the substitution process straightforward.