93.5k views
0 votes
Solve the system of equations using the elimination method:

X + 2y - z = -6
3x - y + z = 8
4x - y - 2z = 0

1 Answer

5 votes

The solution to the given system of equations is x=22/9, y= -26/9 and z=8/3. .

Solving the System of Equations using Elimination Method:

Given System:

X + 2y - z = -6

3x - y + z = 8

4x - y - 2z = 0

Objective:

Solve for x, y, and z.

Steps:

Write the augmented matrix:

| 1 2 -1 | -6 |

| 3 -1 1 | 8 |

| 4 -1 -2 | 0 |

Eliminate y from the second and third rows:

Add -2 times the first row to the second row.

| 1 2 -1 | -6 |

| 0 -5 3 | 20 |

| 4 -1 -2 | 0 |

Add -4 times the first row to the third row.

| 1 2 -1 | -6 |

| 0 -5 3 | 20 |

| 0 -9 -6 | 24 |

Eliminate z from the third row:

Add 2 times the second row to the third row. | 1 2 -1 | -6 | | 0 -5 3 | 20 | | 0 -1 0 | 44 |

Back-solve for x, y, and z:

From the third row, we get -1z = 44, so z = -44.

Substitute this value of z back into the second row to get -5y + 3(-44) = 20, so y = -26/9.

Substitute the values of y and z back into the first row to get x + 2(-26/9) - (-44) = -6, so x = 22/9.

Solution:

x = 22/9

y = -26/9

z = 8/3

Verification:

Substitute the values of x, y, and z back into the original equations:

22/9 + 2(-26/9) - 8/3 = -6

3(22/9) - (-26/9) + 8/3 = 8

4(22/9) - (-26/9) - 2(8/3) = 0

All equations are satisfied, confirming the solution.

Therefore, the solution to the system of equations is x = -3, y = -7/2, and z = 8/(-3), which simplifies to x = 22/9, y = -26/9, and z = 8/3.

User Atasoyh
by
8.0k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories