Question

Solve simultaneous equation 2x + 4y = 1 3x-5y=7

Answer 1

$\left \{ {{2x+4y=1\ \ | *(-3)} \atop {3x-5y=7\ \ | *2}} \right. \\\\ \left \{ {{-6x-12y=-3} \atop {6x-10y=14}} \right.\\+----\\add\ both\ equations\\\\ -22y=11\ \ \ | divide\ by\ -22\\\\ y=-\frac{1}{2}\\\\ 2x=1-4y\ \ | divide\ by\ 2\\\\ x=\frac{1-4y}{2}=\frac{1-4*(-\frac{1}{2})}{2} =\frac{3}{2}$