Question

Resolva os sistemas e indique a resposta correta: x + y = 1 4x + 7y = 10

Answer 1

Resposta:

x = -1; y = 2

Explicação passo-a-passo:

$\left \{ {{x+y=1} \atop {4x+7y=10}} \right. \\x=1-y$

$4(1-y)+7y=10\\4-4y+7y=10\\-4y+7y=10-4\\3y=6\\y=6/3\\y=2$

$x+y=1\\x + 2 = 1\\x = 1-2\\x = -1$

x = -1; y = 2