Question

Determine o conjunto da solução do seguinte sistema x+y=5 x-y=4

Answer 1

$x+y=5,\:x-y=4\\\\\begin{bmatrix}x+y=5\\ x-y=4\end{bmatrix}\\\\\begin{bmatrix}5-y-y=4\end{bmatrix}\\\\\begin{bmatrix}5-2y=4\end{bmatrix}\\\\x=5-\frac{1}{2}\\\\x=\frac{9}{2}\\\\x=\frac{9}{2},\:y=\frac{1}{2}$