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Hello, I need a thorough explanation of how to solve this problem, I am having a little trouble understanding some of the details.

Hello, I need a thorough explanation of how to solve this problem, I am having a little-example-1
User Gisella
by
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1 Answer

25 votes
25 votes

The given equations are

- 5x + 5y - 5z = 0

10x + 2y - 5z = - 6

- 5x + 2y + 3z = 10

Let us divide through the first equation by 5 and make y the subject of the equation. we have

- 5x/5 + 5y/5 - 5z/5 = 0/5

- x + y - z = 0

We would add x and z to both sides of the equation. We have

- x + x + y - z + z = 0 + x + z

y = x + z

The next step is to substitute y = x + z into the second and third equations. Substituting y = x + z into the second equation, we have

10x + 2(x + z) - 5z = - 6

By expanding the parentheses on the left, we have

10x + 2x + 2z - 5z = - 6

8x - 3z = - 6 equation 4

Substituting y = x + z into the third equation, we have

- 5x + 2(x + z) + 3z = 10

By expanding the parentheses on the left, we have

- 5x + 2x + 2z + 3z = 10

- 3x + 5z = 10 equation 5

We would solve equations 4 and 5 by using the method of elimination. We would eliminate x by multiplying equation 4 by 3 and equation 5 by 8. The new equations would be

24x - 9z = - 18

- 24x + 40z = 80

We would add both equations. We have

24x - 24x - 9z + 40z = - 18 + 80

31z = 62

Dividing both sides of the equation by 31,

31z/31 = 62/31

z = 2

Substituting z = 2 into 8x - 3z = - 6, we have

8x - 3(2) = - 6

8x - 6 = - 6

Sdding 6 to both sides of the equation, we have

8x - 6 + 6 = - 6 + 6

8x = 0

Dividing both sides of the equation by 8,

8x/8 = 0/8

x = 0

Finally, we would substitute x = 0 and z = 2 into y = x + z. We have

y = 0 + 2

y = 2

The solution is

(0, 2, 2)

User Ajay Soman
by
2.9k points