Question

1. when the method of substitution is used to solve the system\

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

\
a possible third equation that must be solved is:\
\bigcirc\\ 2(-y + 2) = -1\
\bigcirc\\ 2x + (-x + 2) = 2\
\bigcirc\\ -x + 2 = -1\
\bigcirc\\ 2x + (-x + 2) = -1\
\

1. when solving the following system of equations using the method of substitution,\

equation 1: $x - 2y = 10$\
equation 2: $3x - y = 5$\
which equation must be substituted into the other?\
\bigcirc\\ it doesnt matter which equation you substitute into the other, both ways will work.\
\bigcirc\\ the second equation must be substituted into the first equation.\
\bigcirc\\ the first equation must be substituted into the second equation.\
\bigcirc\\ you cannot use the method of substitution to solve this system.

Explanation:

Answer:

\(2x + (-x + 2) = -1\)
It doesn't matter which equation you substitute into the other, both ways will work.