Question

Qual o resultado do sistema de equação 2x+y= -4 e x+2y = 7 A) x=4 e y=2 B) x= 0 e y=6 C) x= -2 e y=8 D) x= 4 e y=3 E) x=5 e y=1

Answer 1

$\large\boxed{\begin{array}{l}\begin{cases}\sf 2x+y=-4\\\sf x+2y=7\end{cases}\\+\underline{\begin{cases}\sf 2x+y=-4\\\sf-2x-4y=-14\end{cases}}\\\sf -3y=-18\cdot(-1)\\\sf 3y=18\\\sf y=\dfrac{18}{3}\\\sf y=6\\\sf x+2y=7\\\sf x+2\cdot6=7\\\sf x+12=7\\\sf x=7-12\\\sf x=-5\\\sf S=\{(-5,6)\}\\\huge\boxed{\boxed{\boxed{\boxed{\sf\maltese~corrija~o~gabarito}}}}\end{array}}$