solve the following system of equations?

x+5z=30

5x+y=30

y-7z=-30

I am trying to find solutions to this problem. I can't figure it out. someone, please help???

2 Answers

Relevance
  • 1 month ago

    x + 5z = 30...(1)

    5x + y = 30...(2)

    y - 7z = -30...(3)

    We can combine equation (1) and (2) to eliminate x, leaving another equation containing y and z.

    i.e. 5(1) - (2) => 25z - y = 120...(4)

    Now, (3) + (4) => 25z - 7z = 90

    so, 18z = 90

    i.e. z = 90/18 = 5

    Using (3) we get, y - 7(5) = -30

    so, y = 5

    And, using (2) we get, 5x + 5 = 30

    i.e. 5x = 25

    so, x = 5

    Hence, (x, y, z) => (5, 5, 5)

    :)>

    • Commenter avatarLogin to reply the answers
  • 1 month ago

    x+5z=30------(1)

    5x+y=30------(2)

    y-7z=-30------(3)

    (2)-(3)=>

    5x+7z=60----(4)

    5(1)-(4)=>

    25z-7z=90

    =>

    18z=90

    =>

    z=5

    x=5 from (1)

    y=5 from (3)

    • Commenter avatarLogin to reply the answers
Still have questions? Get your answers by asking now.