Read the following passage and answer the given questions. Two algebraic expressions are given as (I) $6x^2 + 29x + P$ and (II) $3x + 1$. (I) is divided by (II) leaving $(2x + 9)$ as quotient and 19 as remainder. Find the value of P.
Aptitude
Elementary Algebra
Difficulty: Medium
Choose an option
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A25
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B26
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C27
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D28
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ENone of these
Answer
Correct Answer: 28
Explanation
### Concept & Polynomial Division Theorem
The division algorithm for polynomials states that when a dividend is divided by a divisor, it yields a quotient and a remainder.
$$ \text{Dividend} = (\text{Divisor} \times \text{Quotient}) + \text{Remainder} $$
### Step-by-Step Solution
* Given Dividend = $6x^2 + 29x + P$
* Given Divisor = $3x + 1$
* Given Quotient = $2x + 9$
* Given Remainder = $19$
* Applying the theorem: $6x^2 + 29x + P = (3x + 1)(2x + 9) + 19$
* Expand the right side: $(3x \times 2x) + (3x \times 9) + (1 \times 2x) + (1 \times 9) + 19$
* Simplify: $6x^2 + 27x + 2x + 9 + 19$
* Combine terms: $6x^2 + 29x + 28$
* Comparing both sides: $6x^2 + 29x + P = 6x^2 + 29x + 28$
* Therefore, $P = 28$.
### Exam Strategy & Shortcut
To find the constant term $P$ quickly, you only need to multiply the constant terms of the divisor and quotient, and then add the remainder. The $x$ terms are irrelevant for finding $P$. Constant of divisor (1) multiplied by constant of quotient (9) plus remainder (19) gives $1 \times 9 + 19 = 28$.
### Common Pitfall
A frequent mistake is forgetting to add the remainder to the product of the divisor and quotient before comparing the coefficients.
### Final Answer
Therefore, the correct answer is **28**.