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The polynomials 2x^3- 7x^2 + ax -6 and x...

The polynomials `2x^3- 7x^2 + ax -6` and `x^3-8x^2 +(2a + 1)x- 16` leave the same remainder when divided by x- 2. Find the value of a

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To solve the problem, we need to find the value of \( a \) such that the two given polynomials leave the same remainder when divided by \( x - 2 \). ### Step-by-step Solution: 1. **Identify the Polynomials**: Let \( f(x) = 2x^3 - 7x^2 + ax - 6 \) and \( g(x) = x^3 - 8x^2 + (2a + 1)x - 16 \). 2. **Find the Remainder When Divided by \( x - 2 \)**: According to the Remainder Theorem, the remainder of a polynomial \( f(x) \) when divided by \( x - c \) is \( f(c) \). Here, we need to evaluate both polynomials at \( x = 2 \). 3. **Calculate \( f(2) \)**: \[ f(2) = 2(2^3) - 7(2^2) + a(2) - 6 \] \[ = 2(8) - 7(4) + 2a - 6 \] \[ = 16 - 28 + 2a - 6 \] \[ = 2a - 18 \] 4. **Calculate \( g(2) \)**: \[ g(2) = (2^3) - 8(2^2) + (2a + 1)(2) - 16 \] \[ = 8 - 8(4) + (4a + 2) - 16 \] \[ = 8 - 32 + 4a + 2 - 16 \] \[ = 4a - 38 \] 5. **Set the Remainders Equal**: Since both polynomials leave the same remainder when divided by \( x - 2 \), we set \( f(2) \) equal to \( g(2) \): \[ 2a - 18 = 4a - 38 \] 6. **Solve for \( a \)**: Rearranging the equation: \[ 38 - 18 = 4a - 2a \] \[ 20 = 2a \] \[ a = \frac{20}{2} = 10 \] ### Final Answer: The value of \( a \) is \( 10 \).
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ICSE-REMAINDER AND FACTOR THEOREMS-Exercise 8A
  1. Find, in each case, the remainder when : (i) x^(4)- 3x^2 + 2x + 1 is...

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  2. Show that : (i) x -2 is a factor of 5x^2+ 15x- 50. (ii) 3x + 2 is ...

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  3. Use the Remainder Theorem to find which of the following is a factor o...

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  4. (i) If 2x + 1 is a factor of 2x^2+ ax- 3, find the value of a. (ii) ...

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  5. Find the values of constants a and b when x- 2 and x + 3 both are the ...

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  6. Find the value of k, if 2x +1 is a factor of (3k+2)x^3 + (k-1).

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  7. Find the value of a, if x -2 is a factor of 2x^5- 6x^4 -2ax^3+ 6ax^2+ ...

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  8. Find the values of m and n so that x-1 and x + 2 both are factors of x...

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  9. When x^3+2x^2-kx+4 . is divided by x - 2. the remainder is k. Find the...

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  10. Find the value of a, if the division of ax^3+ 9x^2 +4x -10 by x + 3 le...

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  11. If x^3+ ax^2+ bx + 6 has x -2 as a factor and leaves a remainder 3 whe...

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  12. The expression 2x^3+ ax^2+ bx -2 leaves remainder 7 and 0 when divided...

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  13. What number should be added to 3x^3-5x^2+6x so that when resulting pol...

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  14. What number should be subtracted from x^3 + 3x^2 - 8x + 14 so that on...

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  15. The polynomials 2x^3- 7x^2 + ax -6 and x^3-8x^2 +(2a + 1)x- 16 leave t...

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  16. If x-2 is a factor of the expression 2x^3+ax^2+bx - 14 and when the ex...

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  17. Find 'a' if the two polynomials ax^(3)+3x^(2)-9and2x^(3)+4x+a, leaves ...

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