Question

resolva os sistemas
* a){x+y =13 {4x-y=7
*b) {x+y =-5 {-x+y=-6
*c){-7x+y=-8 {7x-3y=-6
* d){m+n=12 {3m-n=-4
*e){-26x+3y=1 {+26x-2y=1
*f){ -3x +4y= -20 {-3y-4y=+2​
AJUDEMMMMMM​

Answer 1

Explicação passo-a-passo:

resolva os sistemas

* a)

{x+y =13

{4x-y=7 (+)

5x= 20

x = 20/5

x = 4

x+y = 13

4+y= 13

y = 13-4

y = 9

___________

*b)

{x+y = -5

{-x+y= -6 (+)

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

2y= -11

y= -11/2

x+y= -5

x-11/2= -5

(2x-11)/2= -10/2

2x-11= -10

2x = -10+11

2x = 1

x = 1/2

___________

*c)

-7x+y= -8

7x-3y= -6 (+)

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

-2y= - 14

y = 14/2

y = 7

-7x+y = -8

-7x+7= -8

-7x= -8-7

-7x= -15

x= 15/7

___________

* d)

m+n=12

3m-n= -4 (+)

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

4m = 8

m = 2

m+ n = 12

2+ n = 12

n = 12-2

n = 10

_____________

*e)

{-26x+3y=1

{+26x-2y=1 (+)

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

y = 2

26x-2y= 1

26x-2.2= 1

26x-4= 1

26x = 1+4

26x= 5

x = 5/26

_____________

*f)

{ -3x +4y= -20

{-3x-4y=+2 (+)

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

-6x= -18

x= 18/6

x= 3

-3x+4y= -20

-3.3+4y= -20

-9+4y = -20

4y= -20+9

4y= -11

y = -11/4