I'm supposed to be using the substitution or elimination technique to solve
\begin{align*}
x + 2y & = 11\\
x – y & = -1
\end{align*}
but for some odd reason I continue getting the wrong answer. For some odd reason I keep getting a graph answer for these, and I know that is wrong since I need to show step-by-step solution. If anyone could kindly help me with these equations, it would be greatly appreciated.
Thank you!
Best Answer
$$ x-y=-1\implies x=y-1\\ \Downarrow\\ x+2y=11\Longleftrightarrow (y-1)+2y=11\Longleftrightarrow 3y=12\Longleftrightarrow y=4\\ \Downarrow\\ x-y=-1\Longleftrightarrow x-4=-1\Longleftrightarrow x=3 $$