Question

What is the solution to the following system? (3x+2y+z = 20 X-4y-Z=-10 2x+y + 2z = 15

Answer 1

Answer:

x = 4; y = 3; z = 2

Step-by-step explanation:

3x + 2y + z = 20

x - 4y - z = -10

2x + y + 2z = 15

6x + 4y + 2z = 40

 x  - 4y  - z   = -10

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7x            + z = 30

 x  - 4y  -    z = -10

8x + 4y  + 8z = 60

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9x            + 7z = 50

z = 30 - 7x

9x + 7(30 - 7x) = 50

9x + 210 - 49x = 50

-40x = -160

x = 4

z = 30 - 7(4)

z = 2

2x + y + 2z = 15

2(4) + y + 2(2) = 15

y = 3

x = 4; y = 3; z = 2