Question

Which is the first step needed to solve by substitution?

Answer 1

$\begin{gathered} -x+y=-1 \\ 2x-y=3 \end{gathered}$

To solve the given system of equations for substitution you:

1. Solve in one of the equations a variable.

For the given options the one that is correct is solve the first equation for y, by adding x to both sides:

$\begin{gathered} -x+x+y=-1+x \\ y=-1+x \end{gathered}$