Question

resolva o sistema

2x+y=40
3x-2y=-10​

Answer 1

$2x + y = 40 \: . \: (2) \\ 3x - 2y = - 10 \\ \\ 4x + 2y = 80 \\ 3x - 2y = - 10 \\ - - - - - - - \\ 7x = 70 \\ x = \frac{70}{7} \\ x = 10. \\ \\ 4 \times 10 + 2y = 80 \\ 40 + 2y = 80 \\ 2y = 80 - 40 \\ 2y = 40 \\ y = \frac{40}{2} \\ y = 20.$