Respuesta :

Answer:

3.  x+y = -1

    x-y = 7

(x+x+y-y) 2x=6

x=3

4. 2x+2y = -2

   3x-2y = 12

(2x+3x+2y-2y) 5x=-2+12

5x=10

x= 2

5. 6x+5y = 4

  -6x+7y = 20

(6x-6x+5y+7y)= 4+20

12y=24

y=2