हिंदी

Show that each one of the following systems of linear equation is inconsistent: x + y − 2z = 5 x − 2y + z = −2 −2x + y + z = 4 - Mathematics

Advertisements
Advertisements

प्रश्न

Show that each one of the following systems of linear equation is inconsistent:

x + y − 2z = 5

x − 2y + z = −2

−2x + y + z = 4

योग
Advertisements

उत्तर

The above system can be written as:

`[(1, 1, -2),(1, -2, 1),(-2, 1, 1)][(x),(y),(z)] = [(5),(-2),(4)]`

or A X = B

`|A| = 1(-3) - 1(3) - 2 (-3) = -3 - 3 + 6 = 0`

So, A is singular. Now the system can be inconsistent, if

(adj A) × B ≠ 0

C11 = −3   C21 = −3   C31 = −3

C12 = −3   C22 = −3   C32 = −3

C13 = −3   C23 = −3   C33 = −3

(adj A) = `[(-3, -3, -3),(-3, -3, -3),(-3, -3, -3)] = [(-3, -3, -3),(-3, -3, -3),(-3, -3, -3)]`

(adj A) × (B) = `[(-3, -3, -3),(-3, -3, -3),(-3, -3, -3)] [(5),(-2),(4)] = [(-15 + 6 - 12),(-15 + 6 -12),(-15 + 6 - 12)]`

= `[(-21),(-21),(-21)]`

≠ 0

Hence, the given system is inconsistent.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 8: Solution of Simultaneous Linear Equations - Exercise 8.1 [पृष्ठ १५]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 12
अध्याय 8 Solution of Simultaneous Linear Equations
Exercise 8.1 | Q 4.6 | पृष्ठ १५

संबंधित प्रश्न

Solve the system of linear equations using the matrix method.

5x + 2y = 4

7x + 3y = 5


Evaluate the following determinant:

\[\begin{vmatrix}\cos \theta & - \sin \theta \\ \sin \theta & \cos \theta\end{vmatrix}\]


Find the value of x, if

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


Without expanding, show that the value of the following determinant is zero:

\[\begin{vmatrix}\sin^2 A & \cot A & 1 \\ \sin^2 B & \cot B & 1 \\ \sin^2 C & \cot C & 1\end{vmatrix}, where A, B, C \text{ are the angles of }∆ ABC .\]


Evaluate the following:

\[\begin{vmatrix}a + x & y & z \\ x & a + y & z \\ x & y & a + z\end{vmatrix}\]


Find the area of the triangle with vertice at the point:

(3, 8), (−4, 2) and (5, −1)


Prove that :

\[\begin{vmatrix}z & x & y \\ z^2 & x^2 & y^2 \\ z^4 & x^4 & y^4\end{vmatrix} = \begin{vmatrix}x & y & z \\ x^2 & y^2 & z^2 \\ x^4 & y^4 & z^4\end{vmatrix} = \begin{vmatrix}x^2 & y^2 & z^2 \\ x^4 & y^4 & z^4 \\ x & y & z\end{vmatrix} = xyz \left( x - y \right) \left( y - z \right) \left( z - x \right) \left( x + y + z \right) .\]

 


Prove that :

\[\begin{vmatrix}a^2 & bc & ac + c^2 \\ a^2 + ab & b^2 & ac \\ ab & b^2 + bc & c^2\end{vmatrix} = 4 a^2 b^2 c^2\]

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 − y = − 2
3x + 4y = 3


5x + 7y = − 2
4x + 6y = − 3


2y − 3z = 0
x + 3y = − 4
3x + 4y = 3


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


2x − 3y − 4z = 29
− 2x + 5y − z = − 15
3x − y + 5z = − 11


x − y + z = 3
2x + y − z = 2
− x − 2y + 2z = 1


x + 2y = 5
3x + 6y = 15


x + y − z = 0
x − 2y + z = 0
3x + 6y − 5z = 0


A salesman has the following record of sales during three months for three items A, B and C which have different rates of commission 

Month Sale of units Total commission
drawn (in Rs)
  A B C  
Jan 90 100 20 800
Feb 130 50 40 900
March 60 100 30 850


Find out the rates of commission on items A, B and C by using determinant method.


If I3 denotes identity matrix of order 3 × 3, write the value of its determinant.


Write the value of 

\[\begin{vmatrix}\sin 20^\circ & - \cos 20^\circ\\ \sin 70^\circ& \cos 70^\circ\end{vmatrix}\]

Write the cofactor of a12 in the following matrix \[\begin{bmatrix}2 & - 3 & 5 \\ 6 & 0 & 4 \\ 1 & 5 & - 7\end{bmatrix} .\]


If \[\begin{vmatrix}x + 1 & x - 1 \\ x - 3 & x + 2\end{vmatrix} = \begin{vmatrix}4 & - 1 \\ 1 & 3\end{vmatrix}\], then write the value of x.

If \[\begin{vmatrix}2x & 5 \\ 8 & x\end{vmatrix} = \begin{vmatrix}6 & - 2 \\ 7 & 3\end{vmatrix}\] , write the value of x.


If \[A + B + C = \pi\], then the value of \[\begin{vmatrix}\sin \left( A + B + C \right) & \sin \left( A + C \right) & \cos C \\ - \sin B & 0 & \tan A \\ \cos \left( A + B \right) & \tan \left( B + C \right) & 0\end{vmatrix}\]  is equal to 


Solve the following system of equations by matrix method:
3x + y = 19
3x − y = 23


Solve the following system of equations by matrix method:
 x − y + z = 2
2x − y = 0
2y − z = 1


Solve the following system of equations by matrix method:
 x + y + z = 6
x + 2z = 7
3x + y + z = 12


Show that the following systems of linear equations is consistent and also find their solutions:
2x + 2y − 2z = 1
4x + 4y − z = 2
6x + 6y + 2z = 3


Show that each one of the following systems of linear equation is inconsistent:
4x − 2y = 3
6x − 3y = 5


Show that each one of the following systems of linear equation is inconsistent:
4x − 5y − 2z = 2
5x − 4y + 2z = −2
2x + 2y + 8z = −1


2x − y + z = 0
3x + 2y − z = 0
x + 4y + 3z = 0


3x − y + 2z = 0
4x + 3y + 3z = 0
5x + 7y + 4z = 0


If \[\begin{bmatrix}1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1\end{bmatrix}\begin{bmatrix}x \\ y \\ z\end{bmatrix} = \begin{bmatrix}1 \\ - 1 \\ 0\end{bmatrix}\], find x, y and z.

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


If A = `[[1,1,1],[0,1,3],[1,-2,1]]` , find A-1Hence, solve the system of equations: 

x +y + z = 6

y + 3z = 11

and x -2y +z = 0


The cost of 4 dozen pencils, 3 dozen pens and 2 dozen erasers is ₹ 60. The cost of 2 dozen pencils, 4 dozen pens and 6 dozen erasers is ₹ 90. Whereas the cost of 6 dozen pencils, 2 dozen pens and 3 dozen erasers is ₹ 70. Find the cost of each item per dozen by using matrices


For what value of p, is the system of equations:

p3x + (p + 1)3y = (p + 2)3

px + (p + 1)y = p + 2

x + y = 1

consistent?


The number of real value of 'x satisfying `|(x, 3x + 2, 2x - 1),(2x - 1, 4x, 3x + 1),(7x - 2, 17x + 6, 12x - 1)|` = 0 is


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×