Mathematics for IGCSE & O level - Equations (Section 5 - No. 2)
What is the first step in solving simultaneous equations using substitution?
Eliminate one of the variables.
Isolate one of the variables in one of the equations.
Substitute the value of one variable into the other equation.
Solve for both variables simultaneously.
Explication
The first step is to isolate one of the variables in one of the equations to then substitute its value into the other equation.