Question

resolva os sistemas 2x menos y = 5 x + y = 4

Answer 1

2x - y = 5
x + y = 4 (-2)

====> 2x - y = 5
-2x - 2y = -8
↓
-3y = -3 (-1) ===> 3y = 3 ==> y = 3
↓
2x - 3 = 5 => x = 4