Question

X+2y=7
X+y=-5 com resposta completa

Answer 1

x+2y = 7                         x + y = -5
(-5-y)+2y = 7                   x= -5 - y
-5-3y = 7
-3y = 7 + 5
-3y = 12
y = 12/-3
Y = - 4

x + (-4)=-5
x -4 = -5
x = -5 + 4
X = -1

R: -4, -1

Answer 2

$\left \{ {{x = 7 -2y } \atop {x +y = -5}} \right.$

7 -2y +y = 5
-y = 5 -7
y = 2

x = 7 -2(2)
x = 7 -4
x = 3