Math Problem Statement

answer system 1 using cramer's rule

Solve the system using determinants (Cramer's Rule).

Solution

To solve the first system using determinants (Cramer's Rule), let's first rewrite the system of equations in standard form. The system is:

3y+2xz=13y + 2x - z = 1 3x+2z=85y3x + 2z = 8 - 5y 3z1=x2y3z - 1 = x - 2y

Rearrange each equation:

  1. 2x+3yz=12x + 3y - z = 1
  2. 3x+5y+2z=83x + 5y + 2z = 8
  3. x+2y+3z=1-x + 2y + 3z = 1

Now, we have the system in the form Ax=BAx = B, where AA is the matrix of coefficients, xx is the vector of variables, and BB is the constant matrix.

The coefficient matrix AA, variable vector XX, and constant vector BB are:

A=(231352123),X=(xyz),B=(181)A = \begin{pmatrix} 2 & 3 & -1 \\ 3 & 5 & 2 \\ -1 & 2 & 3 \end{pmatrix}, \quad X = \begin{pmatrix} x \\ y \\ z \end{pmatrix}, \quad B = \begin{pmatrix} 1 \\ 8 \\ 1 \end{pmatrix}

To find the values of xx, yy, and zz using Cramer's Rule, we calculate the determinant of AA and the determinants of matrices obtained by replacing each column of AA with BB.

  1. Compute det(A)\det(A):

    det(A)=231352123\det(A) = \begin{vmatrix} 2 & 3 & -1 \\ 3 & 5 & 2 \\ -1 & 2 & 3 \end{vmatrix}

  2. Compute det(Ax)\det(A_x): Replace the first column of AA with BB.

    Ax=(131852123)A_x = \begin{pmatrix} 1 & 3 & -1 \\ 8 & 5 & 2 \\ 1 & 2 & 3 \end{pmatrix}

  3. Compute det(Ay)\det(A_y): Replace the second column of AA with BB.

    Ay=(211382113)A_y = \begin{pmatrix} 2 & 1 & -1 \\ 3 & 8 & 2 \\ -1 & 1 & 3 \end{pmatrix}

  4. Compute det(Az)\det(A_z): Replace the third column of AA with BB.

    Az=(231358121)A_z = \begin{pmatrix} 2 & 3 & 1 \\ 3 & 5 & 8 \\ -1 & 2 & 1 \end{pmatrix}

Once we have each determinant, apply Cramer's Rule:

x=det(Ax)det(A),y=det(Ay)det(A),z=det(Az)det(A)x = \frac{\det(A_x)}{\det(A)}, \quad y = \frac{\det(A_y)}{\det(A)}, \quad z = \frac{\det(A_z)}{\det(A)}

I will calculate these determinants and provide the solution values for xx, yy, and zz.The solution to the system using Cramer's Rule is:

x=3,y=1,z=2x = 3, \quad y = -1, \quad z = 2

Would you like further details on any step or have any questions?

Here are five related questions to deepen your understanding:

  1. How does Cramer's Rule work with a 3x3 system in terms of determinant replacement?
  2. What would happen if the determinant of AA were zero?
  3. Can Cramer's Rule be used for systems larger than 3x3, and what challenges might arise?
  4. How can we verify the solution obtained from Cramer's Rule by substituting back into the original equations?
  5. Are there alternative methods to solve this system of equations?

Tip: Cramer's Rule is only applicable when the determinant of the coefficient matrix AA is non-zero, ensuring a unique solution.

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Math Problem Analysis

Mathematical Concepts

Linear Algebra
Systems of Linear Equations
Determinants
Cramer's Rule

Formulas

Determinant of a 3x3 matrix: det(A) = a(ei − fh) − b(di − fg) + c(dh − eg)
Cramer's Rule: x = det(A_x)/det(A), y = det(A_y)/det(A), z = det(A_z)/det(A)

Theorems

Cramer's Rule

Suitable Grade Level

Grades 11-12 or College Level