Question

0.4x+0.5y=2.5

1.2x-3.5y=2.5




ELIMINATION BY USING MULTIPLICATION

Answer 1

`\begin{cases} 0.4x+0.5y=2.5\ \ /*7 \\ 1.2x-3.5y=2.5\end{cases} \\ \\ \begin{cases} 2.8x+3.5y=17.5 \\ 1.2x-3.5y=2.5\end{cases}\\ +\ \ -------- \\4x=20 \ \ /:4\\ \\x=5`


`0.4x+0.5y=2.5\\ \\ 0.4*5+0.5y=2.5\\ \\2+0.5y=2.5\ \ | -2\\ \\0.5y=2.5-2\\ \\0.5y=0.5 \ \ :/ \ 0.5\\ \\ y=1 \\ \\ \begin{cases}\ \x=5 \\ y=1 \end{cases}`