Question

1 ) resolva os sistemas E ) { x + 2 y = - 1 - x + y = - 2

Answer 1

x + 2y = -1
-x + y = - 2

x + 2y = -1
x = -1 - 2y

-x + y = -2
-(-1 - 2y) + y = -2
1 + 2y + y = -2
3y = -2 - 1
3y - -3
y = -1
 
x = -1 - 2y
x = -1 - 2(-1)
x = -1 + 2
x = 1