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Find the term independent of x in (2x^(2...

Find the term independent of `x` in `(2x^(2) - (1)/(x) )^(12)`.

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To find the term independent of \( x \) in the expression \( (2x^2 - \frac{1}{x})^{12} \), we will use the Binomial Theorem. ### Step-by-Step Solution: 1. **Identify the general term**: The general term \( T_{r+1} \) in the binomial expansion of \( (a + b)^n \) is given by: \[ T_{r+1} = \binom{n}{r} a^{n-r} b^r \] Here, \( a = 2x^2 \), \( b = -\frac{1}{x} \), and \( n = 12 \). Thus, the general term becomes: \[ T_{r+1} = \binom{12}{r} (2x^2)^{12-r} \left(-\frac{1}{x}\right)^r \] 2. **Simplify the general term**: Expanding this, we get: \[ T_{r+1} = \binom{12}{r} (2^{12-r} (x^2)^{12-r}) \left(-\frac{1}{x}\right)^r \] This simplifies to: \[ T_{r+1} = \binom{12}{r} 2^{12-r} (-1)^r x^{2(12-r) - r} \] Therefore: \[ T_{r+1} = \binom{12}{r} 2^{12-r} (-1)^r x^{24 - 3r} \] 3. **Find the term independent of \( x \)**: For the term to be independent of \( x \), the exponent of \( x \) must be zero: \[ 24 - 3r = 0 \] Solving for \( r \): \[ 3r = 24 \quad \Rightarrow \quad r = 8 \] 4. **Substitute \( r \) back into the general term**: Now, we substitute \( r = 8 \) back into the expression for \( T_{r+1} \): \[ T_{9} = \binom{12}{8} 2^{12-8} (-1)^8 \] This simplifies to: \[ T_{9} = \binom{12}{8} 2^4 \] 5. **Calculate \( \binom{12}{8} \)**: We know that \( \binom{12}{8} = \binom{12}{4} \): \[ \binom{12}{4} = \frac{12!}{4!(12-4)!} = \frac{12!}{4!8!} = \frac{12 \times 11 \times 10 \times 9}{4 \times 3 \times 2 \times 1} = 495 \] 6. **Calculate \( 2^4 \)**: \[ 2^4 = 16 \] 7. **Final calculation**: Now, we can find the term independent of \( x \): \[ T_{9} = 495 \times 16 = 7920 \] ### Conclusion: The term independent of \( x \) in the expansion of \( (2x^2 - \frac{1}{x})^{12} \) is **7920**.
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