Need help on matrices using cramer's rule

In summary: This is an example of "Cramer's Rule" for solving a system of equations.In summary, the conversation discusses the use of Cramer's Rule to solve a system of equations and confirms that the solution x = 1, y = -1, z = 2 is correct. The person also asks if this equation is considered a dependent equation and is provided with an explanation.
  • #1
qdv
4
0
I am learning how to solve a matrice using cramer's rule, and not sure if this is the correct answer.

Solve the following systems of equations
x - y + 3z = 8
3x + y - 2z = -2
2x + 4y + z = 0
so I figured out the solution is x = 1, y = -1, z = 2

but is this equation consider a
dependent equation that all solutions that satisfy x - y + 3z = 8 ??

thanks
 
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  • #2
qdv said:
I am learning how to solve a matrice using cramer's rule, and not sure if this is the correct answer.

Solve the following systems of equations
x - y + 3z = 8
3x + y - 2z = -2
2x + 4y + z = 0
so I figured out the solution is x = 1, y = -1, z = 2

thanks

It's okay.The solution satisfies all equations and it's unique,therefore...Congratulations! :smile:

Daniel.
 
  • #3
Online calculator

I solve it using a online calculator and I got

Cramer rule's solver step by step
Coeficients Matrix
1 -1 3 8
3 1 -2 -2
2 4 1 0
Δ = determinant1 -1 3
3 1 -2
2 4 1
Δ sub x = det8 -1 3
-2 1 -2
0 4 1
Δ sub y = det1 8 3
3 -2 -2
2 0 1
Δ sub z = det1 -1 8
3 1 -2
2 4 0
Δ = det1 -1 3
3 1 -2
2 4 1
1 -1 3
3 1 -2

[(1) (1) (1) + (3) (4) (3) + (2) (-1) (-2)] - [(3) (-1) (1) + (1) (4) (-2) + (2) (1) (3)]
(1) + (36) + (4)- (-3) + (-8) + (6)
( 41) - ( -5)
Δ = 46

Δx = det8 -1 3
-2 1 -2
0 4 1
8 -1 3
-2 1 -2

[(8) (1) (1) + (-2) (4) (3) + (0) (-1) (-2)] - [(-2) (-1) (1) + (8) (4) (-2) + (0) (1) (3)]
(8) + (-24) + (0)- (2) + (-64) + (0)
( -16) - ( -62)
Δx = 46

Δy = det1 8 3
3 -2 -2
2 0 1
1 8 3
3 -2 -2

[(1) (-2) (1) + (3) (0) (3) + (2) (8) (-2)] - [(3) (8) (1) + (1) (0) (-2) + (2) (-2) (3)]
(-2) + (0) + (-32)- (24) + (0) + (-12)
( -34) - ( 12)
Δy = -46

Δz = det1 -1 8
3 1 -2
2 4 0
1 -1 8
3 1 -2

[(1) (1) (0) + (3) (4) (8) + (2) (-1) (-2)] - [(3) (-1) (0) + (1) (4) (-2) + (2) (1) (8)]
(0) + (96) + (4)- (0) + (-8) + (16)
( 100) - ( 8)
Δz = 92

x =46/46

y =-46/46

z =-46/46

x =1

y =-1

z =2

-------
www.algebrasolver.totalh.com
 
Last edited:
  • #4
qdv said:
I am learning how to solve a matrice using cramer's rule, and not sure if this is the correct answer.

Solve the following systems of equations
x - y + 3z = 8
3x + y - 2z = -2
2x + 4y + z = 0
so I figured out the solution is x = 1, y = -1, z = 2

but is this equation consider a
dependent equation that all solutions that satisfy x - y + 3z = 8 ??

thanks
What do you mean by "this equation"? It's not at all clear what your question is. Yes, as dextercioby said, and you could easily have checked, x= 1, y= -1, z= 2 satisfies the three equations and, since the determinant of coefficients is not 0, is the only solution to that system of equations.
 

Related to Need help on matrices using cramer's rule

1. What is Cramer's Rule?

Cramer's Rule is a method for solving systems of linear equations using determinants. It is named after Swiss mathematician Gabriel Cramer and is based on the ratio of determinants.

2. How does Cramer's Rule work?

Cramer's Rule uses determinants to find the solutions to a system of linear equations. It involves finding the determinant of the coefficient matrix, and then substituting in the values from the constant matrix to find the solutions for each variable.

3. When should I use Cramer's Rule?

Cramer's Rule is most useful when solving systems of linear equations with a small number of variables. It is also helpful when trying to find the solution to a single variable in a larger system.

4. What are the advantages of using Cramer's Rule?

One advantage of Cramer's Rule is that it provides a systematic way to solve systems of linear equations. It also allows for the solution of individual variables in a larger system. Additionally, it can be used to check the accuracy of solutions found through other methods.

5. Are there any limitations to using Cramer's Rule?

One limitation of Cramer's Rule is that it can only be used for systems of linear equations with the same number of equations as variables. It is also not efficient for larger systems, as the number of determinants that need to be calculated increases rapidly with the number of variables.

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