Question

Aiudaa con los procedimientos

a) 4x + 5y = 21

- 4x + 8 = -8

b) 3x +2y =23

2x – 2y = 2


C) 2x – 4y = - 2

3x + 4y = 17

d) x + 2y = 8

- x + 3y = 17




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Answer 1

Respuesta:

a)

4x + 5y = 21

-4x + 8y = -8

Como el sistema ya está igualado, lo que procede es eliminar "x", luego resolver y despejar "y" entonces:

13y = 13

y = 13/13

y = 1

reemplazas "y" en cualquiera de las 2 ecuaciones y despejas "x"

4x + 5y = 21

4x + 5(1) = 21

4x + 5 = 21

4x = 21 - 5

4x = 16

x = 16/4

x = 4

Comprobación

4x + 5y = 21

4(4) + 5(1) = 21

16 + 5 = 21

21 = 21

-4x + 8y = -8

-4(4) + 8(1) = -8

-16 + 8 = -8

-8 = -8

b)

3x + 2y =23

2x – 2y = 2

5x = 25

x = 25/5

x = 5

3x + 2y = 23

3(5) + 2y = 23

15 + 2y = 23

2y = 23 - 15

2y = 8

y = 8/2

y = 4

Comprobación

3x + 2y =23

3(5) + 2(4) = 23

15 + 8 = 23

23 = 23

2x – 2y = 2

2(5) - 2(4) = 2

10 - 8 = 2

2 = 2

C)

2x – 4y = - 2

3x + 4y = 17

5x = 15

x = 15/5

x = 3

2x - 4y = -2

2(3) - 4y = -2

6 - 4y = -2

-4y = -2 - 6

-4y = -8

y = -8/-4

y = 2

Comprobación

2x – 4y = - 2

2(3) - 4(2) = -2

6 - 8 = -2

-2 = -2

3x + 4y = 17

3(3) + 4(2) = 17

9 + 8 = 17

17 = 17

d)

x + 2y = 8

- x + 3y = 17

5y = 25

y = 25/5

y = 5

x + 2y = 8

x + 2(5) = 8

x + 10 = 8

x = 8 - 10

x = -2

Comprobación

x + 2y = 8

-2 + 2(5) = 8

-2 + 10 = 8

8 = 8

- x + 3y = 17

- (-2) + 3(5) = 17

2 + 15 = 17

17 = 17

Explicación paso a paso: