Question

resolva os sistemas : x-y-2=0 2x+y-7=0

Answer 1

  x - y = 2
2x + y = 7
--------------
  3x   = 9
    x = 9/3
    x = 3

x - y = 2
3 - y = 2
- y = 2 - 3
- y = - 1 .(-1)
  y = 1                   S = { ( 3 , 1 ) }