Question

1) resolva o sistema


a){x+y=11
{x-y=3

b {x-y=1
{x+y=9

Answer 1

a){x+y=11

{x-y=3

x = 3 + y

x+y = 11

3 + y + y = 11

2y = 11 - 3

2y = 8

y = 8/2

y = 4

x-y = 3

x - 4 = 3

x = 3 + 4

x = 7

b {x-y=1

{x+y=9

x = 1 + y

1 + y + y = 9

2y = 9 - 1

2y = 8

y = 8/2

y = 4

x+ y = 9

x + 4 = 9

x = 9 - 4

x = 5