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Show that (x-5) is a factor of x^(3)-3x^...

Show that (x-5) is a factor of `x^(3)-3x^(2)-4x-30`.

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To show that \( (x - 5) \) is a factor of the polynomial \( x^3 - 3x^2 - 4x - 30 \), we can use the Factor Theorem. According to the Factor Theorem, \( (x - a) \) is a factor of a polynomial \( f(x) \) if and only if \( f(a) = 0 \). ### Step-by-Step Solution: 1. **Identify the Polynomial**: Let \( f(x) = x^3 - 3x^2 - 4x - 30 \). 2. **Set Up for the Factor Theorem**: We need to check if \( (x - 5) \) is a factor. According to the Factor Theorem, we need to evaluate \( f(5) \). 3. **Substitute \( x = 5 \) into the Polynomial**: \[ f(5) = 5^3 - 3(5^2) - 4(5) - 30 \] 4. **Calculate Each Term**: - Calculate \( 5^3 \): \[ 5^3 = 125 \] - Calculate \( 3(5^2) \): \[ 5^2 = 25 \quad \Rightarrow \quad 3 \times 25 = 75 \] - Calculate \( 4(5) \): \[ 4 \times 5 = 20 \] 5. **Combine the Results**: Now substitute these values back into the equation: \[ f(5) = 125 - 75 - 20 - 30 \] 6. **Perform the Arithmetic**: - First, combine the negative terms: \[ -75 - 20 - 30 = -125 \] - Now combine with \( 125 \): \[ 125 - 125 = 0 \] 7. **Conclusion**: Since \( f(5) = 0 \), by the Factor Theorem, \( (x - 5) \) is indeed a factor of the polynomial \( x^3 - 3x^2 - 4x - 30 \). ### Final Statement: Thus, we have shown that \( (x - 5) \) is a factor of the polynomial \( x^3 - 3x^2 - 4x - 30 \). ---
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Show that : (i) x-5, is factor of x^(2)-11x+30 " " (ii) (x+2 , is a factor of x^(2)+3x+2 (iii) x-3, is a factor of 2x^(3)+7x^(2)-24x-45 " " (iv) 3x-2 , is a factor of 3x^(3)+x^(2)-20x+12 (v) x-1, is a factor of x^(3)-10x^(2)+23x-14 " " (vi) x-2 , is a factor of x^(3)-3x^(2)-x+6