Matemáticas, pregunta formulada por pattyhernandezhuerta, hace 6 meses

quien me puede ayudar porfavor ​

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Respuestas a la pregunta

Contestado por eribertheau
2

Ejercicios hechos por reducción

a)

5x - 2y = 2

x + 2y = 2

5x + x - 2y + 2y = 2 + 2

6x = 4

x = 4/6

x = 2/3

x + 2y = 2

2/3 + 2y = 2

2y = 2 - 2/3

2y = 6/3 - 2/3

2y = 4/3

y = 4/3 / 2

y = 4/6

y = 2/3

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b)

5x - y = 3. (4)

-2x + 4y = -12

20x - 4y = 12

-2x + 4y = -12

20x - 2x - 4y + 4y = 12 - 12

18x = 0

x = 0

5x - y = 3

5(0) - y = 3

0 - y = 3

y = -3

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c)

3x + 5y = 15 (-2)

2x - 3y = -9 (3)

-6x - 10y = -30

6x - 9y = -27

-6x + 6x - 10y - 9y = -30 - 27

-19y = -57

y = 57/19

y = 3

2x - 3y = -9

2x - 3(3) = -9

2x - 9 = -9

2x = -9 + 9

2x = 0

x = 0

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

d)

4x + 6y = 2 (3)

6x + 5y = 1 (-2)

12x + 18y = 6

-12x - 10y = -2

12x - 12x + 18y - 10y = 6 - 2

8y = 4

y = 4/8

y = 1/2

4x + 6y = 2

4x + 6(1/2) = 2

4x + 6/2 = 2

4x + 3 = 2

4x = 2 - 3

4x = -1

x = - 1/4

Ejercicios hechos por igualación

a)

3x + 4y = 9

2x + 3y = 7

3x = 9 - 4y

x = (9 - 4y) / 3

2x = 7 - 3y

x = (7 - 3y) / 2

x = x

(9 - 4y) / 3 = (7 - 3y) / 2

(9 - 4y)(2) = (7 - 3y)(3)

18 - 8y = 21 - 9y

18 - 21 = - 9y + 8y

-3 = -y

y = 3

3x + 4y = 9

3x + 4(3) = 9

3x + 12 = 9

3x = 9 - 12

3x = -3

x = -3/3

x = -1

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b)

5x - 3y = 9

-2x + 6y = -2

5x = 9 + 3y

x = (9 + 3y) / 5

-2x + 6y = -2

-2x = -2 - 6y

x = (-2 - 6y) / -2

x = x

(9 + 3y) / 5 = (-2 - 6y) / -2

(9 + 3y)(-2) = (-2 - 6y)(5)

-18 - 6y = -10 - 30y

-18 + 10 = -30y + 6y

-8 = -24y

y = 8/24

y = 1/3

5x - 3y = 9

5x - 3(1/3) = 9

5x - 1 = 9

5x = 9 + 1

5x = 10

x = 10/5

x = 2

Ejercicios hechos por sustitución

a)

-3x + 5y = 3

4x + 2y = -4

4x + 2y = -4

2y = -4 - 4x

y = (- 4 - 4x) / 2

y = -2 - 2x

-3x + 5y = 3

-3x + 5(-2 - 2x) = 3

-3x - 10 - 10x = 3

-13x - 10 = 3

-13x = 3 + 10

-13x = 13

x = 13/-13

x = -1

4x + 2y = -4

4(-1) + 2y = -4

-4 + 2y = -4

2y = 0

y = 0

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

b)

4x - 5y = 2

5x + 3y = 21

4x - 5y = 2

4x = 2 + 5y

x = (2 + 5y) / 4

5x + 3y = 21

5{(2 + 5y) / 4} + 3y = 21

(10 + 25y) / 4 + 3y = 21

(10 + 25y + 12y) / 4 = 21

10 + 25y + 12y = 21(4)

10 + 37y = 84

37y = 84 - 10

37y = 74

y = 74/37

y = 2

4x - 5y = 2

4x - 5(2) = 2

4x - 10 = 2

4x = 2 + 10

4x = 12

x = 12/4

x = 3


pattyhernandezhuerta: muchas gracias
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