Question

Qual o conjunto solução do sistema a seguir? 3x -y = 13 x - 4y = -3​

Answer 1

$\large\boxed{\begin{array}{l}\begin{cases}\rm 3x-y=13\\\rm x-4y=-3\cdot(-3)\end{cases}\\\\+\underline{\begin{cases}\rm\diagdown\!\!\!\!\!\!3x-y=13\\\rm-\diagdown\!\!\!\!\!3x+12y=9\end{cases}}\\\rm 11y=22\\\rm y=\dfrac{22}{11}\\\\\rm y=2\\\rm x-4y=-3\\\rm x=4y-3\\\rm x=4\cdot2-3\\\rm x=8-3\\\rm x=5\\\rm S=\{(5,2)\}\end{array}}$