Question

solve using elimination. show steps plz
3x-7y+10=0, y-2x-3=0

Answer 1

\( {
\begin{array}{llll}
3x-7y+10=0\\
y-2x-3=0
\end{array}\implies
\begin{array}{llll}
3x-7y+10=0\\
-2x+y-3=0
\end{array}\impliedby
\begin{array}{llll}
\textit{first, we arrange the "x" and}\\
\textit{"y" to be in the same column}
\end{array}
\\ \quad \\ \quad \\
\begin{array}{ccccll}
3x-7y+10=0&\implies &3x\cancel{-7y}+10=0\\
-2x+y-3=0&{\color{brown}{ \times 7}}\implies &-14x\cancel{+7y}-21=0
\\\hline\\
&&\square ?+\square ?=\square ?
\end{array}
}\)

notice, arrange the "x" and "y" first
so they're all in the same column, vertically

Answer 2

we multiplied the bottom one, by 7
that way we end up with a +7y at the bottom
that cancels out the -7y atop

sum them up, vertically
see what you end up with

Answer 3

\(\textit{wow, this guy uses another latex symbol} \implies \textit{there are many way to show math notations}\\\textit {wonder why he uses {1111} after each of array and why it doesn't work here} \\\textit{when I imitate his latex to get a gap between the context}\\t\textit {Which key did he use???}\)