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3 years ago

Solve the system of equations 5x+9y+9z=5 4x+9y+6z=10 2x+2y+5z=9

Mathematics

1 answer:

erma4kov [3.2K]3 years ago

4 0

Answer:

{x,y,z} = {-116,28,37}

Step-by-step explanation:

// Solve equation [3] for the variable z

[3] 5z = -2x - 2y + 9

[3] z = -2x/5 - 2y/5 + 9/5

__________________________________________________________

// Plug this in for variable z in equation [1]

[1] 5x + 9y + 9•(-2x/5-2y/5+9/5) = 5

[1] 7x/5 + 27y/5 = -56/5

[1] 7x + 27y = -56

__________________________________________________________

// Plug this in for variable z in equation [2]

[2] 4x + 9y + 6•(-2x/5-2y/5+9/5) = 10

[2] 8x/5 + 33y/5 = -4/5

[2] 8x + 33y = -4

__________________________________________________________

// Solve equation [2] for the variable y

[2] 33y = -8x - 4

[2] y = -8x/33 - 4/33

__________________________________________________________

// Plug this in for variable y in equation [1]

[1] 7x + 27•(-8x/33-4/33) = -56

[1] 5x/11 = -580/11

[1] 5x = -580

__________________________________________________________

// Solve equation [1] for the variable x

[1] 5x = - 580

[1] x = - 116

__________________________________________________________

// By now we know this much :

x = -116

y = -8x/33-4/33

z = -2x/5-2y/5+9/5

__________________________________________________________

// Use the x value to solve for y

y = -(8/33)(-116)-4/33 = 28

__________________________________________________________

// Use the x and y values to solve for z

z = -(2/5)(-116)-(2/5)(28)+9/5 = 37

╦────────────────────────────╦

│Hope this helped _____________________│

│~Derelis ____________________________ │

╨___________________________________╨

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