Question

método de sustitución
7x+3y-4z=-35
3x-2y+5z=38
x+y-6z=-27
por favor ayúdenme
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Answer 1

7x + 3y - 4z = - 35

3x - 2y + 5z = 38

x + y - 6z = - 27

7x + 3y - 4z = - 35 +

3x - 2y + 5z = 38

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

10x + y + z = 3..........(1)

3x - 2y + 5z = 38 +

x + y - 6z = - 27

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

4x - y - z = 11............(2)

7x + 3y - 4z = - 35 +

x + y - 6z = - 27

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

8x + 4y - 10z = - 62..(3)

Sumamos (1) y (2):

10x + y + z = 3..........(1) +

4x - y - z = 11............(2)

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

14x = 14

x = 1

En (3):

8x + 4y - 10z = - 62..(3)

8 + 4y - 10z = - 62

4y - 10z = - 70

2y - 5z = - 35

2y + 35 = 5z.............(4)

x + y - 6z = - 27

1 + y - 6z = - 27

y = - 28 + 6z.............(5)

(5) en (4):

2y + 35 = 5z

2(- 28 + 6z) + 35 = 5z

- 56 + 12z + 35 = 5z

7z = 21

z = 3

En (1):

10x + y + z = 3..........(1)

10 + y + 3 = 3

13 + y = 3

y = - 10

x = 1

y = - 10

z = 3