Question

resolva os sistemas e encontre o par ordenado que representa cada um:

c)x-y=6
x+y=7

d)x+2y=7
x-y=5

e)x+y=11
x-y=3

f)x-y=6
x+y=7

g)x+y=9
x-y=5

h)yx-y=8
x+y=7​

Answer 1

Resposta:

c)x-y= 6 (-1)

x+y= -7

-x+y= -6

x+y= -7

2y= -13

y= -13

       2

x-y= 6

x-(-13/2)= 6

x+13= 6

   2

x= 6 - 13

           2

x= -1/2

S={-1/2, -13/2)

d)X+2y=7

x+y=5      y=5-x    

X+2(5-x)=7

x+10-2x=7

-x=7-10

-x=-3  (-1)

x=3

Y=5-3

y=2

X= 3 Y= 2

-------------------

X+2y=7               X=7-2y

X+y=5

7-2y+y=5

-y=5-7

-y=-2 (-1)

y=2

X=7-2y

X=7-4

X=3    

e){x + y = 11

{x - y = 3

2x = 14

x = 7

x + y = 11

7 + y = 11

y = 11 - 7

y = 4

S = { 7 ; 4 }

f) x-y= 6 (-1)

x+y= -7

-x+y= -6

x+y= -7

2y= -13

y= -13

       2

x-y= 6

x-(-13/2)= 6

x+13= 6

   2

x= 6 - 13

           2

x= -1/2

S={-1/2, -13/2)

g)x + y = 9

x - y = 5

_________

2x = 14

x = 14/2

x = 7

y = 9 - 7

y = 2

Explicação passo a passo: