Question

para amanhã,desesperado,por favor me ajudem.
*calcular a solução (x,y) de cada sistema*.​

Answer 1

a)

x = -3

x - y = -7

-3 - y = -7

- y = -7 + 3

- y = -4

 y = 4

R: S = (-7, 4)

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b)

2x - y = 15

y = -3

2x = 12

x = 12/2

x = 6

R: S = (-3, 6)

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c)

-3x+ 2y = -1

y = -2

-3x+ 2y = -1

-2y = -4

-3x = -5

x = -5/-3

x = 5/3

R: S = (5/3, -4)

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d)

- x = -2 → x = 2

2x - 3y = 13

-2x = -4

2x - 3y = 13

-3y = 9

y = 9/(-3)

y = -3

R: S = (2, -3)

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e)

7x - 3y = 12

2x + 3y = 10

9x = 22

x = 22/9

2 * (22/9) + 3y = 10

(44/9) - 10 = 3y

(44 - 90) / 9 = 3y

-46/9 = 3y

y = -46/(9*3)

y = -46/27

R: S = (22/9, -46/27)

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f)

2x + 4y = 5

-2x - 5y = -1

-y = 4

y = -4

2x + 4y = 5

2x + 4* (-4) = 5

2x - 16 = 5

2x = 16+5

2x = 21

x = 10,5

R: S = (10,5 ; -4)

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g)

x + 3y = 20

-2x - y = 3

2x + 6y = 40

-2x - y = 3

5y = 43

y = 43/5

y = 8,6

x + 3y = 20

x = 20 - (3 * 8,6)

x = - 5,8

R: S = (-5,8 ; -8,6)

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h)

3x + y = -2

x - y = 3

4x = 1

x = 4

x - y = 3

4 - y = 3

y = 4 - 3

y = 1

R: S (4, 1)

Espero ter ajudado.