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Maths help please!! the question is:?

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Maths help please!! the question is:?

find a set of parametric equations for the line in 3 space described by the general equations x-y-z=4 and x+y-5z = 12

thanku very much

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  1. Let z be the free parameter (denoted by t), then z=t

    x-y-t=4...(1)

    x+y-5t=12...(2)

    (2)-(1): 2y-4t=8 => y=2t+4

    (1)+(2): 2x-6t=16 => x=3t+8


  2. You have given us two equations of planes:

    x - y - z = 4

    x + y - 5z = 12

    When these planes intersect, they will do so at a line. We will solve this using matrices (ignore the dots):

    | 1 -1 -1 | 4.. |

    | 1 .1 -5 | 12 |.....R2 → R2 - R1

    | 1 -1 -1 | 4 |

    | 0 .2 -4 | 8 |

    Let z = t:

    2y - 4t = 8

    2y = 8 + 4t

    y = 4 + 2t

    x - y - z = 4

    x - (4 + 2t) - t = 4

    x = 4 + t + (4 + 2t)

    x = 8 + 3t

    =========================

    Your parametric equations are:

    x = 8 + 3t

    y = 4 + 2t

    z = t

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