Question

como resolver essa equação 2x+7y=17 + 5x-y= -13

Answer 1

$\left \{ {{2x+7y=-13} \atop {17+5x-y=-13}} \right. \\ \\ \left \{ {{2x+7y=-13} \atop {y=5x+4}} \right. \\ \\ 2x+7(5x+4)=-13 \\ 2x+35x+28=-13 \\ 37x=-41 \\ x= \frac{-41}{37} \\ \\ y=5. (\frac{-41}{37})+4 \\ \\ y= \frac{-205}{37} +4 \\ \\ y= \frac{-205+148}{37} \ \\ \ y= \frac{-57}{37}$