Question

resolva os sistemas x+y=12 3x-y=16 e x+y=27 x-y=13

Answer 1

Bom dia

a)

x + y = 12
3x - y = 16

soma
4x = 28
x = 7 

7 + y = 12
y = 5

b)

x + y = 27
x - y = 13

soma

2x = 40
x = 20

20 + y = 27
y = 7