Question

{7x+y=5888
{4x-y=6112

Answer 1

Boa noite

 7x + y = 5888,
 4x - y =  6112

11x = 5888 + 6112 = 12000 
x = 12000/11

84000/11 + y = 5888
y = 5888*11/11 - 84000/11 
y = (64768 - 84000)/11 = -19232/11

Answer 2

{7x+y=5888
{4x-y=6112

corta os y

7x+4x=5888+6112
11x=12000
x=12000/11

7x+y=5888
(7*12000)/11+y=5888
84000/11+y=5888
y=(5888*11)/11 - 84000/11
y = (64768-84000)/11
y= -19232/11