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If |(4x,6x+2,8x+1),(6x+2,9x+3,12x),(8x+1...

If `|(4x,6x+2,8x+1),(6x+2,9x+3,12x),(8x+1,12x,16x+2)|` = 0 then x =

A

0

B

`-11`

C

97

D

`-11//97`

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The correct Answer is:
To solve the determinant equation \( |(4x, 6x+2, 8x+1), (6x+2, 9x+3, 12x), (8x+1, 12x, 16x+2)| = 0 \), we will follow these steps: ### Step 1: Set Up the Determinant We start with the determinant: \[ D = \begin{vmatrix} 4x & 6x + 2 & 8x + 1 \\ 6x + 2 & 9x + 3 & 12x \\ 8x + 1 & 12x & 16x + 2 \end{vmatrix} \] ### Step 2: Row Operations To simplify the determinant, we can perform row operations. We will modify the second and third rows to eliminate the \(x\) terms. 1. **Row 2**: Replace \( R_2 \) with \( R_2 - \frac{3}{2} R_1 \) 2. **Row 3**: Replace \( R_3 \) with \( R_3 - 2 R_1 \) After performing these operations, we calculate the new rows: - For \( R_2 \): \[ R_2 = (6x + 2 - \frac{3}{2} \cdot 4x, 9x + 3 - \frac{3}{2} \cdot (6x + 2), 12x - \frac{3}{2} \cdot (8x + 1)) \] Simplifying gives: \[ R_2 = (0, 0, 0) \] - For \( R_3 \): \[ R_3 = (8x + 1 - 2 \cdot 4x, 12x - 2 \cdot (6x + 2), 16x + 2 - 2 \cdot (8x + 1)) \] Simplifying gives: \[ R_3 = (0, -4, 0) \] Now the determinant looks like: \[ D = \begin{vmatrix} 4x & 6x + 2 & 8x + 1 \\ 0 & 0 & 0 \\ 0 & -4 & 0 \end{vmatrix} \] ### Step 3: Calculate the Determinant The determinant of a matrix with a row of zeros is zero. Therefore, we have: \[ D = 0 \] ### Step 4: Solve for \(x\) Since the determinant is equal to zero, we need to find the values of \(x\) that satisfy the original determinant being zero. We can analyze the conditions under which the rows are linearly dependent. From our operations, we can see that the first row is dependent on the second and third rows. This leads us to set up the equations based on the coefficients of \(x\): 1. From the first row, we have the coefficients of \(x\): - \(4x\) - \(6x + 2\) - \(8x + 1\) Setting the determinant to zero gives us the condition for linear dependence. ### Step 5: Solve the Equation To find \(x\), we can set up the equation based on the coefficients: \[ -8(8x + 1) + 3(6x + 2) = 0 \] Expanding and simplifying: \[ -64x - 8 + 18x + 6 = 0 \\ -46x - 2 = 0 \\ 46x = -2 \\ x = -\frac{2}{46} = -\frac{1}{23} \] ### Final Answer Thus, the value of \(x\) is: \[ x = -\frac{1}{23} \]
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ML KHANNA-DETERMINANTS -Self Assessment Test
  1. If |(4x,6x+2,8x+1),(6x+2,9x+3,12x),(8x+1,12x,16x+2)| = 0 then x =

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  2. If a != b != c, are value of x which satisfies the equation |(0,x -a...

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  3. |(b+c,a,a),(b,c+a,b),(c,c,a+b)|=

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  4. |(1,1,1),(a,b,c),(a^3,b^3,c^3)|=

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  5. |(1/a,a^2,bc),(1/b,b^2,ca),(1/c,c^2,ab)|=

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  6. If x=-9 is a root of |(x,3,7),(2,x,2),(7,6,x)|=0 then other two roots ...

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  7. The solution of the equation |(x,2,-1),(2,5,x),(-1,2,x)| = 0 are

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  8. The roots of the equation |(0,x,16),(x,5,7),(0,9,x)| = 0 are

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  9. |(a+b,b+c,c+a),(b+c,c+a,a+b),(c+a,a+b,b+c)|=k|(a,b,c),(b,c,a),(c,a,b)|...

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  10. A root of the equation |(3-x,-6,3),(-6,3-x,3),(3,3,-6-x)| = 0

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  11. If |(-a^2,ab,ac),(ab,-b^2,bc),(ac,bc,-c^2)|=ka^2b^2c^2 , then k =

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  12. If omega!=1 is a cube root of unity and Delta=|(x+omega^(2),omega,1)...

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  13. |((a^x+a^(-x))^2,(a^x-a^(-x))^(2),1),((b^x+b^(-x))^2,(b^x-b^(-x))^(2),...

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  14. The number of values of k which the linear equations 4x+ky+2z=0 kx...

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  15. The value of k for which the set of equationsx + ky + 3z=0, 3x + ky – ...

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  16. If x + y +z=0, 4x+3y -z=0 and 3x + 5y +3z=0 is the given system of equ...

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  17. The system of equations x + y + z=2, 3x – y +2z=6 and 3x + y +z=-18 ha...

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  18. The system of equations x+y+z=6, x+2y + 3z= 10, x+2y + lamdaz=mu has n...

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  19. The system of linear equations x1 + 2x2 + x3 = 3, 2x1 + 3x2 + x3 = 3...

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  20. Let a,b,c be such that b(a+c) ne 0 . If |(a,a+1,a-1),(-b,b+1,b-1),(c...

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