मराठी

Using the matrix method, solve the following system of linear equations: 2x+3y+10z = 4, 4x-6y+5z = 1, 6x+9y-20z = 2.

Advertisements
Advertisements

प्रश्न

Using the matrix method, solve the following system of linear equations:

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

बेरीज
Advertisements

उत्तर

The given system of equations can be written in the form AX = B,

Where, A = `[(2, 3, 10),(4, -6, 5),(6, 9, -20)]`, X = `[(1//x),(1//y),(1//z)]` and B = `[(4),(1),(2)]`

Now, |A| = `|(2, 3, 10),(4, -6, 5),(6, 9, -20)|`

= 2(120 – 45) – 3(–80 – 30) + 10(36 + 36)

= 2(75) – 3(–100) + 10(72)

= 150 + 330 + 720

= 1200 ≠ 0

∴ A–1 exists.

∴ adj A = `[(75, 110, 72),(150, -100, 0),(75, 30, -24)]^T = [(75, 150, 75),(110, -100, 30),(72, 0, -24)]`

Hence, A–1 = `1/|A| (adjA) = 1/1200[(75, 150, 75),(110, -100, 30),(72, 0, -24)]`

As, AX = B

`\implies` X = A–1B

`\implies [(1/x),(1/y),(1/z)] = 1/1200[(75, 150, 75),(110, -100, 30),(72, 0, -24)][(4),(1),(2)]`

= `1/1200[(300 + 150 + 150),(440 - 100 + 60),(288 + 0 - 48)]`

 `\implies [(1/x),(1/y),(1/z)] = 1/1200[(600),(400),(240)] = [(1/2),(1/3),(1/5)]`

Thus, `1/x = 1/2, 1/y = 1/3, 1/z = 1/5`

Hence, x = 2, y = 3, z = 5.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
2022-2023 (March) Official

संबंधित प्रश्‍न

Let A be a nonsingular square matrix of order 3 × 3. Then |adj A| is equal to ______.


If \[A = \begin{bmatrix}2 & 5 \\ 2 & 1\end{bmatrix} \text{ and } B = \begin{bmatrix}4 & - 3 \\ 2 & 5\end{bmatrix}\] , verify that |AB| = |A| |B|.

 

Find the value of x, if

\[\begin{vmatrix}3x & 7 \\ 2 & 4\end{vmatrix} = 10\] , find the value of x.


Find the value of x, if

\[\begin{vmatrix}x + 1 & x - 1 \\ x - 3 & x + 2\end{vmatrix} = \begin{vmatrix}4 & - 1 \\ 1 & 3\end{vmatrix}\]


Evaluate the following:

\[\begin{vmatrix}0 & x y^2 & x z^2 \\ x^2 y & 0 & y z^2 \\ x^2 z & z y^2 & 0\end{vmatrix}\]


Prove that
\[\begin{vmatrix}- bc & b^2 + bc & c^2 + bc \\ a^2 + ac & - ac & c^2 + ac \\ a^2 + ab & b^2 + ab & - ab\end{vmatrix} = \left( ab + bc + ca \right)^3\]


Prove the following identity:

\[\begin{vmatrix}a + x & y & z \\ x & a + y & z \\ x & y & a + z\end{vmatrix} = a^2 \left( a + x + y + z \right)\]

 


Prove the following identity:

`|(a^3,2,a),(b^3,2,b),(c^3,2,c)| = 2(a-b) (b-c) (c-a) (a+b+c)`

 


Prove that :

\[\begin{vmatrix}a + b & b + c & c + a \\ b + c & c + a & a + b \\ c + a & a + b & b + c\end{vmatrix} = 2\begin{vmatrix}a & b & c \\ b & c & a \\ c & a & b\end{vmatrix}\]

 


Prove that

\[\begin{vmatrix}a^2 & 2ab & b^2 \\ b^2 & a^2 & 2ab \\ 2ab & b^2 & a^2\end{vmatrix} = \left( a^3 + b^3 \right)^2\]

Prove that

\[\begin{vmatrix}a^2 + 1 & ab & ac \\ ab & b^2 + 1 & bc \\ ca & cb & c^2 + 1\end{vmatrix} = 1 + a^2 + b^2 + c^2\]

2x + 3y = 10
x + 6y = 4


9x + 5y = 10
3y − 2x = 8


5x − 7y + z = 11
6x − 8y − z = 15
3x + 2y − 6z = 7


If A and B are non-singular matrices of the same order, write whether AB is singular or non-singular.


If x ∈ N and \[\begin{vmatrix}x + 3 & - 2 \\ - 3x & 2x\end{vmatrix}\]  = 8, then find the value of x.


Let \[A = \begin{bmatrix}1 & \sin \theta & 1 \\ - \sin \theta & 1 & \sin \theta \\ - 1 & - \sin \theta & 1\end{bmatrix},\text{ where 0 }\leq \theta \leq 2\pi . \text{ Then,}\]




If \[\begin{vmatrix}2x & 5 \\ 8 & x\end{vmatrix} = \begin{vmatrix}6 & - 2 \\ 7 & 3\end{vmatrix}\] , then x = 

 


The value of \[\begin{vmatrix}1 & 1 & 1 \\ {}^n C_1 & {}^{n + 2} C_1 & {}^{n + 4} C_1 \\ {}^n C_2 & {}^{n + 2} C_2 & {}^{n + 4} C_2\end{vmatrix}\] is


Solve the following system of equations by matrix method:
2x + y + z = 2
x + 3y − z = 5
3x + y − 2z = 6


If A = `[(1, 2, 0), (-2, -1, -2), (0, -1, 1)]`, find A−1. Using A−1, solve the system of linear equations   x − 2y = 10, 2x − y − z = 8, −2y + z = 7.


x + y + z = 0
x − y − 5z = 0
x + 2y + 4z = 0


Solve the following for x and y: \[\begin{bmatrix}3 & - 4 \\ 9 & 2\end{bmatrix}\binom{x}{y} = \binom{10}{ 2}\]


For the system of equations:
x + 2y + 3z = 1
2x + y + 3z = 2
5x + 5y + 9z = 4


Transform `[(1, 2, 4),(3, -1, 5),(2, 4, 6)]` into an upper triangular matrix by using suitable row transformations


If `|(2x, 5),(8, x)| = |(6, 5),(8, 3)|`, then find x


`abs ((2"xy", "x"^2, "y"^2),("x"^2, "y"^2, 2"xy"),("y"^2, 2"xy", "x"^2)) =` ____________.


The existence of unique solution of the system of linear equations x + y + z = a, 5x – y + bz = 10, 2x + 3y – z = 6 depends on 


The value of λ, such that the following system of equations has no solution, is

`2x - y - 2z = - 5`

`x - 2y + z = 2`

`x + y + lambdaz = 3`


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×