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Find the value of 'k' for which x=3 is a...

Find the value of 'k' for which `x=3` is a solution of the quadratic equation, `(k+2)x^(2)-kx+6=0`
Hence, find the other root of the equation.

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To solve the problem step by step, we need to find the value of \( k \) such that \( x = 3 \) is a solution of the quadratic equation \( (k + 2)x^2 - kx + 6 = 0 \). Then, we will find the other root of the equation. ### Step 1: Substitute \( x = 3 \) into the equation Since \( x = 3 \) is a solution, we substitute \( x = 3 \) into the equation: \[ (k + 2)(3^2) - k(3) + 6 = 0 \] ### Step 2: Simplify the equation Calculating \( 3^2 \): \[ (k + 2)(9) - 3k + 6 = 0 \] Expanding this gives: \[ 9k + 18 - 3k + 6 = 0 \] ### Step 3: Combine like terms Combine the terms involving \( k \) and the constant terms: \[ (9k - 3k) + (18 + 6) = 0 \] This simplifies to: \[ 6k + 24 = 0 \] ### Step 4: Solve for \( k \) Now, we isolate \( k \): \[ 6k = -24 \] Dividing both sides by 6: \[ k = -4 \] ### Step 5: Substitute \( k \) back into the equation Now that we have \( k = -4 \), we substitute it back into the original quadratic equation: \[ (-4 + 2)x^2 - (-4)x + 6 = 0 \] This simplifies to: \[ -2x^2 + 4x + 6 = 0 \] ### Step 6: Divide the entire equation by -2 To make the equation simpler, divide by -2: \[ x^2 - 2x - 3 = 0 \] ### Step 7: Factor the quadratic equation Now, we factor the quadratic: \[ (x - 3)(x + 1) = 0 \] ### Step 8: Find the roots Setting each factor to zero gives us the roots: \[ x - 3 = 0 \quad \Rightarrow \quad x = 3 \] \[ x + 1 = 0 \quad \Rightarrow \quad x = -1 \] ### Conclusion Thus, the other root of the equation is: \[ \text{Other root} = -1 \]
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Find the value of k for which x=2 is a solution of the equation kx^2+2x-3=0

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Knowledge Check

  • If x=2 is a solution of the quadratic equation kx^(2) + 2x- 3= 0 , then the value of k is:

    A
    `-1`
    B
    `-4`
    C
    `(1)/(4)`
    D
    `-(1)/(4)`
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