Question

{ x - 5y = 8
{ 3x + 4y = 5

Me ajudem pfv

Answer 1

$\begin{cases}x-5y=8\\ 3x+4y=5\end{cases}\\\\\\ x=8+5y\\\\ 3\cdot(8+5y)+4y=5\\ 24+15y+4y=5\\ 24+19y=5\\ 19y=5-24\\ 19y=-19\\\\ y= \dfrac{-19}{~~19} \\\\ \Large\boxed{y=-1}\\\\\\ x=8+5y\\ x=8+5\cdot(-1)\\ x=8-5\\\\ \Large\boxed{x=-3}\\\\\\ \Large\boxed{\text{S}=\{(3,-1)\}}$