Question

Solve the system of equations.
3x + 2y + z = 10
9x - 6y+z = 0
x-y-3z = -10

Answer 1

Answer: option B

Explanation:

Answer 2

x = 1

y = 2

z = 3

Explanation:

3x + 2y + z = 10 | ×3 |

9x - 6y + z = 0 | ×1 |

9x + 6y + 3z = 30

9x - 6y + z = 0

_______________--

12y + 2z = 30..... (4)

3x + 2y + z = 10 | ×1 |

x - y - 3z = -10 | ×3 |

3x + 2y + z = 10

3x - 3y - 9z = -30

_______________--

5y + 10z = 40........ (5)

4 and 5

12y + 2z = 30 | ×5 |

5y + 10z = 40 | ×1 |

60y + 10z = 150

5y + 10z = 40

_____________--

55y = 110

y = 110/55

y = 2

5y + 10z = 40

5(2) + 10z = 40

10 + 10z = 40

10z = 40 - 10

10z = 30

z = 30/10

z = 3

x - y - 3z = -10

x - 2 - 3(3) = -10

x - 2 - 9 = -10

x - 11 = -10

x = -10 + 11

x = 1