Question

determine x e y sabendo que
(2x + 5y) = (17)
(x - y) = (5)

Answer 1

$\left \{ {{2x + 5y=17} \atop {x - y=5--\ \textgreater \ .5}} \right. --\ \textgreater \ \left \{ {{2x+5y=17} \atop {5x-5y=25}} \right. +--\ \textgreater \ 7x=42;x= \frac{42}{7} --\ \textgreater \ x=6;$ $x - y=5--\ \textgreater \ 6-y=5--\ \textgreater \ 6-5=y--\ \textgreater \ y=1--\ \textgreater \ (6;5)$