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Solve the system below using matrices. 2x-y 2z = 6, -x + y= -z ,-x - 3z = -6

User Ionel Lupu
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1 Answer

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The solution to the system of equations is x = -4.5, y = 4, and z = 0.5.

The solution to the system of equations using matrices, along with an explanation of the steps involved:

Step 1: Represent the system of equations as a matrix equation

The given system of equations can be represented as a matrix equation in the form:

AX = B

where:

A is the coefficient matrix, which consists of the coefficients of the variables in the equations

X is the column vector of variables, which consists of the variables to be solved for

B is the column vector of right-hand side constants

In this case, the coefficient matrix A, the column vector of variables X, and the column vector of right-hand side constants B are given as follows:

A = [[2, -1, 2],

[-1, 1, -1],

[-1, 0, -3]]

X = [[x],

[y],

[z]]

B = [[6],

[-1],

[-6]]

Therefore, the matrix equation representing the system of equations is:

[[2, -1, 2],

[-1, 1, -1],

[-1, 0, -3]] * [[x],

[y],

[z]] = [[6],

[-1],

[-6]]

Step 2: Solve the matrix equation using matrix inversion

To solve the system of equations using matrices, we can invert the coefficient matrix A and multiply both sides of the matrix equation by the inverse of A. This gives us:

X = A^(-1) * B

where A^(-1) is the inverse of the coefficient matrix A.

In this case, the inverse of the coefficient matrix A can be calculated using a matrix inversion algorithm, such as the Gaussian elimination method. The inverse of A is:

A^(-1) = [[0.5, 0.5, -0.5],

[-0.5, 1, -0.5],

[0.5, 0, -0.25]]

Multiplying both sides of the matrix equation by A^(-1), we get:

[[x],

[y],

[z]] = [[0.5, 0.5, -0.5],

[-0.5, 1, -0.5],

[0.5, 0, -0.25]] * [[6],

[-1],

[-6]]

Expanding the matrix multiplication, we get the following system of equations:

0.5x + 0.5y - 0.5z = 6

-0.5x + y - 0.5z = -1

0.5x - 0.25z = -6

Step 3: Solve the system of equations using back-substitution

We can now solve the system of equations using back-substitution. To do this, we first solve the third equation for x:

x = -4.5

Substituting this value of x into the second equation, we get

4.5y - 0.5z = -1

Solving for y, we get:

y = 4

Substituting the values of x and y into the first equation, we get:

-9 - 4z = 6

Solving for z, we get:

z = 0.5

Therefore, the solution to the system of equations is x = -4.5, y = 4, and z = 0.5.

User Metalim
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