Question

I am in desperate need of assistance!!! if i dont get this answer right theyre going to take everything i have, even my dog, so please help me out. your help will be very much appreciated and i will forever be grateful for a stranger to help me.Explain what method you would use to solve the following system:

3x + 4y – 5z = -3
-5x -2y + 6z = 5
4x – 8y + 3z = -10

please if you can explain the steps. thank you very much!!!!!!

Answers

  1. Answer:
    {x,y,z} = {-3,-1,-2}
    Step-by-step explanation:
    // Solve equation [3] for the variable  z
     [3]    3z = -4x + 8y – 10
     [3]    z = -4x/3 + 8y/3 – 10/3
    // Plug this in for variable  z  in equation [1]
      [1]    3x + 4y – 5•(-4x/3+8y/3-10/3) = -3
      [1]    29x/3 – 28y/3 = -59/3
      [1]    29x – 28y = -59
    // Plug this in for variable  z  in equation [2]
      [2]    -5x – 2y + 6•(-4x/3+8y/3-10/3) = 5
      [2]    -13x + 14y = 25
    // Solve equation [2] for the variable  y
     [2]    14y = 13x + 25
     [2]    y = 13x/14 + 25/14
    // Plug this in for variable  y  in equation [1]
      [1]    29x – 28•(13x/14+25/14) = -59
      [1]    3x = -9
    // Solve equation [1] for the variable  x
      [1]    3x = – 9
      [1]    x = – 3
    // By now we know this much :
       x = -3
       y = 13x/14+25/14
       z = -4x/3+8y/3-10/3
    // Use the  x  value to solve for  y
       y = (13/14)(-3)+25/14 = -1
    // Use the  x  and  y  values to solve for  z
     z = -(4/3)(-3)+(8/3)(-1)-10/3 = -2

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