Home
Class 12
MATHS
Using matrices, solve the following syst...

Using matrices, solve the following system of equations for x,y and z.
`3x-2y+3z=8`,`2x+y-z=1`, `4x-3y+2z=4`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the system of equations using matrices, we will follow these steps: Given equations: 1. \( 3x - 2y + 3z = 8 \) (Equation 1) 2. \( 2x + y - z = 1 \) (Equation 2) 3. \( 4x - 3y + 2z = 4 \) (Equation 3) ### Step 1: Write the equations in matrix form \( AX = B \) We can express the system of equations in the form of matrices: \[ A = \begin{pmatrix} 3 & -2 & 3 \\ 2 & 1 & -1 \\ 4 & -3 & 2 \end{pmatrix}, \quad X = \begin{pmatrix} x \\ y \\ z \end{pmatrix}, \quad B = \begin{pmatrix} 8 \\ 1 \\ 4 \end{pmatrix} \] ### Step 2: Calculate the determinant of matrix \( A \) (denoted as \( \Delta \)) The determinant \( \Delta \) of matrix \( A \) can be calculated using the formula for the determinant of a 3x3 matrix: \[ \Delta = a(ei - fh) - b(di - fg) + c(dh - eg) \] Where: \[ A = \begin{pmatrix} a & b & c \\ d & e & f \\ g & h & i \end{pmatrix} \] For our matrix \( A \): \[ \Delta = 3 \cdot (1 \cdot 2 - (-1) \cdot (-3)) - (-2) \cdot (2 \cdot 2 - (-1) \cdot 4) + 3 \cdot (2 \cdot (-3) - 1 \cdot 4) \] Calculating this step by step: \[ = 3 \cdot (2 - 3) + 2 \cdot (4 + 4) + 3 \cdot (-6 - 4) \] \[ = 3 \cdot (-1) + 2 \cdot 8 + 3 \cdot (-10) \] \[ = -3 + 16 - 30 = -17 \] ### Step 3: Calculate \( \Delta_x \) (replace the first column of \( A \) with \( B \)) To find \( \Delta_x \): \[ \Delta_x = \begin{vmatrix} 8 & -2 & 3 \\ 1 & 1 & -1 \\ 4 & -3 & 2 \end{vmatrix} \] Calculating \( \Delta_x \): \[ = 8 \cdot (1 \cdot 2 - (-1) \cdot (-3)) - (-2) \cdot (1 \cdot 2 - (-1) \cdot 4) + 3 \cdot (1 \cdot (-3) - 1 \cdot 4) \] \[ = 8 \cdot (2 - 3) + 2 \cdot (2 + 4) + 3 \cdot (-3 - 4) \] \[ = 8 \cdot (-1) + 2 \cdot 6 + 3 \cdot (-7) \] \[ = -8 + 12 - 21 = -17 \] ### Step 4: Calculate \( \Delta_y \) (replace the second column of \( A \) with \( B \)) To find \( \Delta_y \): \[ \Delta_y = \begin{vmatrix} 3 & 8 & 3 \\ 2 & 1 & -1 \\ 4 & 4 & 2 \end{vmatrix} \] Calculating \( \Delta_y \): \[ = 3 \cdot (1 \cdot 2 - (-1) \cdot 4) - 8 \cdot (2 \cdot 2 - (-1) \cdot 4) + 3 \cdot (2 \cdot 4 - 1 \cdot 4) \] \[ = 3 \cdot (2 + 4) - 8 \cdot (4 + 4) + 3 \cdot (8 - 4) \] \[ = 3 \cdot 6 - 8 \cdot 8 + 3 \cdot 4 \] \[ = 18 - 64 + 12 = -34 \] ### Step 5: Calculate \( \Delta_z \) (replace the third column of \( A \) with \( B \)) To find \( \Delta_z \): \[ \Delta_z = \begin{vmatrix} 3 & -2 & 8 \\ 2 & 1 & 1 \\ 4 & -3 & 4 \end{vmatrix} \] Calculating \( \Delta_z \): \[ = 3 \cdot (1 \cdot 4 - 1 \cdot (-3)) - (-2) \cdot (2 \cdot 4 - 1 \cdot 4) + 8 \cdot (2 \cdot (-3) - 1 \cdot 4) \] \[ = 3 \cdot (4 + 3) + 2 \cdot (8 - 4) + 8 \cdot (-6 - 4) \] \[ = 3 \cdot 7 + 2 \cdot 4 + 8 \cdot (-10) \] \[ = 21 + 8 - 80 = -51 \] ### Step 6: Calculate the values of \( x, y, z \) Using Cramer's Rule: \[ x = \frac{\Delta_x}{\Delta}, \quad y = \frac{\Delta_y}{\Delta}, \quad z = \frac{\Delta_z}{\Delta} \] Substituting the values we found: \[ x = \frac{-17}{-17} = 1 \] \[ y = \frac{-34}{-17} = 2 \] \[ z = \frac{-51}{-17} = 3 \] ### Final Answer: The solution to the system of equations is: \[ x = 1, \quad y = 2, \quad z = 3 \]
Promotional Banner

Topper's Solved these Questions

  • DETERMINANTS

    MODERN PUBLICATION|Exercise OBJECTIVE TYPE QUESTIONS (Multiple choice question)|25 Videos
  • DETERMINANTS

    MODERN PUBLICATION|Exercise OBJECTIVE TYPE QUESTIONS (Fill in the blanks)|10 Videos
  • DETERMINANTS

    MODERN PUBLICATION|Exercise Exercise 4(h) (SHORT ANSWER TYPE QUESTIONS)|10 Videos
  • CONTINUITY AND DIFFERENTIABILITY

    MODERN PUBLICATION|Exercise CHAPTER TEST|12 Videos
  • DIFFERENTIAL EQUATIONS

    MODERN PUBLICATION|Exercise CHAPTER TEST (9)|12 Videos

Similar Questions

Explore conceptually related problems

Using matrices, solve the following system of equations for x,y and z. {:(x+2y+z=8),(2x+y-z=1),(x-y+z=2):}

Using matrices, solve the following system of equations for x,y and z. x+y+z=3 , y+3z=4 , x-2y+z=0

Using matrices, solve the following system of equations for x,y and z. 2x+3y+3z=5 , x-2y+z=-4 , 3x-y-2z=3

Using matrices, solve the following system of equations for x,y and z. x+y-z=-1 , 3x+y-2z=3 , x-y-z=-1

Using matrices, solve the following system of equations for x,y and z. 2x+y+z=1 , x-2y-z=(3)/(2) , 3y-5z=9 .

Using matrices,solve the following system of equations: 3x-y+z=5 ,2x-2y+3z=7,x+y-z=-1

Using matrices,solve the following system of equations: x+y+z=2,2x-y=3,2y+z=0

Using matrices,solve the following system of equations: x+2y+z=7,x+3z=11,2x-3y=1

Using matrices,solve the following system of equations: x-y+z=4;2x+y-3z=0;x+y+z=2

Using matrices,solve the following system of equations: x+y+z=6;x+2z=73x+y+z=12

MODERN PUBLICATION-DETERMINANTS-Exercise 4(h) (LONG ANSWER TYPE QUESTIONS)
  1. Using matrices, solve the following system of equations for x,y and z....

    Text Solution

    |

  2. Using matrices, solve the following system of equations for x,y and z....

    Text Solution

    |

  3. Using matrices, solve the following system of equations for x,y and z....

    Text Solution

    |

  4. Using matrices, solve the following system of equations for x,y and z....

    Text Solution

    |

  5. Solve system of linear equations, using matrix method, in questions 7 ...

    Text Solution

    |

  6. Solve the following equations, using inverse of a matrix : {:(x-2y+3...

    Text Solution

    |

  7. Solve the following equations, using inverse of a matrix : {:(x+2y=5...

    Text Solution

    |

  8. Find inverse of matrix, solve the equation x-y+z=4,2x+y-3z=0,x+y+z=2

    Text Solution

    |

  9. Solve the following equations, using inverse of a matrix : {:(x+2y-3...

    Text Solution

    |

  10. 2x+3y+5z=16, 3x+ 2y-4z= 4, x + y - 2z =- 3.

    Text Solution

    |

  11. Solve the following equations, using inverse of a matrix : {:(2x+y+z...

    Text Solution

    |

  12. Solve the following equations, using inverse of a matrix : {:(2x+3y+...

    Text Solution

    |

  13. Solve the following equations, using inverse of a matrix : {:(3x+4y+...

    Text Solution

    |

  14. Solve the following equations, using inverse of a matrix : {:(8x+4y+...

    Text Solution

    |

  15. Solve the following equations, using inverse of a matrix : {:(x+y+z=...

    Text Solution

    |

  16. Solve the following equations, using inverse of a matrix : {:(5x-y+z...

    Text Solution

    |

  17. Solve the following equations, using inverse of a matrix : {:(3x-2y+...

    Text Solution

    |

  18. Solve the following equations, using inverse of a matrix : {:(3x-y+z...

    Text Solution

    |

  19. Solve the following equations, using inverse of a matrix : {:(4x+3y+...

    Text Solution

    |

  20. 2/x+3/y+10/z=4, 4/x-6/y+5/z=1, 6/x+9/y-20/z=2

    Text Solution

    |