Question

Resolva o sistema de equações.
2x + y = 11
x - y = 4​

Answer 1

$\large\boxed{\begin{array}{l}+\underline{\begin{cases}\sf 2x+\diagup\!\!\!y=11\\\sf x-\diagup\!\!\!y=4\end{cases}}\\\sf3x=15\\\sf x=\dfrac{15}{3}\\\sf x=5\\\sf x-y=4\\\sf y=x-4\\\sf y=5-4\\\sf y=1\\\sf S=\{5,1\}\end{array}}$