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How to solve the following system of equations for all 3 variables

How to solve the following system of equations for all 3 variables-example-1

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The solutions to the following system of equation is x = 0, y = 2, z = 5.

Solving system of equation using Gaussian Elimination

Gaussian Elimination is an approach for solving systems of linear equations that involves reducing the augmented matrix of the system into a smaller, row-equivalent matrix which corresponds to the given system of equations.

Given the system of equation:

5x + 9y - 3z = 3 ------ (1)

-3x - 9y + 4z = 2 ------(2)

4x + 9y - 5z = -7 ------(3)

Multiply first equation by 3/5 and add the result to the second equation, we have:

5x + 9y - 3z = 3

-18/5y + 11/5z = 19/5

4x + 9y - 5z = -7

Multiply first equation by -4/5 and add the result to the third equation, we have:

5x + 9y - 3z = 3

-18/5y + 11/5z = 19/5

9/5y - 13/5z = -47/5

Remove the fractions by multiplying second and the third equation by 5, we have:

5x + 9y - 3z = 3

-18y + 11z = 19

9y - 13z = -47

Multiply second equation by 1/2 and add the result to the third equation, we have:

5x + 9y - 3z = 3

-18y + 11z = 19

-15/2z = -75/2

Remove the fractions by multiplying third equation by 2, we have;

5x + 9y - 3z = 3

-18y + 11z = 19

-15z = -75

Divide the third equation by 15, we have:

5x + 9y - 3z = 3

-18y + 11z = 19

-z = -5

Solve for z

z = 5

From the second equation, let's solve for y:

-18y + 11z = 19

-18y + (11×5) = 19

-18y + 55 = 19

-18y = 19 - 55

-18y = -36

y = 2

Replace the value of y and z into the first equation to solve for x;

5x + 9y - 3z = 3

5x + 9(2) - 3(5) = 3

5x + 3 = 3

5x = 0

x = 0/5

x = 0

Therefore, the solutions to the following system of equation is x = 0, y = 2, z = 5.

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