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Find the constant term in the expansion of `(2x^(4)-(1)/(3x^(7)))^(11)`

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To find the constant term in the expansion of \( (2x^4 - \frac{1}{3x^7})^{11} \), we will follow these steps: ### Step 1: Identify the General Term The general term \( T_{r+1} \) in the binomial expansion of \( (a + b)^n \) is given by: \[ T_{r+1} = \binom{n}{r} a^{n-r} b^r \] In our case, \( a = 2x^4 \), \( b = -\frac{1}{3x^7} \), and \( n = 11 \). Therefore, the general term becomes: \[ T_{r+1} = \binom{11}{r} (2x^4)^{11-r} \left(-\frac{1}{3x^7}\right)^r \] ### Step 2: Simplify the General Term Now, we simplify the general term: \[ T_{r+1} = \binom{11}{r} (2^{11-r} (x^4)^{11-r}) \left(-\frac{1}{3}\right)^r (x^{-7})^r \] This can be rewritten as: \[ T_{r+1} = \binom{11}{r} 2^{11-r} (-1)^r \frac{1}{3^r} x^{4(11-r) - 7r} \] \[ = \binom{11}{r} 2^{11-r} (-1)^r \frac{1}{3^r} x^{44 - 4r - 7r} \] \[ = \binom{11}{r} 2^{11-r} (-1)^r \frac{1}{3^r} x^{44 - 11r} \] ### Step 3: Find the Constant Term The constant term occurs when the exponent of \( x \) is zero: \[ 44 - 11r = 0 \] Solving for \( r \): \[ 11r = 44 \implies r = 4 \] ### Step 4: Substitute \( r \) into the General Term Now we substitute \( r = 4 \) back into the general term to find the constant term: \[ T_{5} = \binom{11}{4} 2^{11-4} (-1)^4 \frac{1}{3^4} \] Calculating each part: \[ \binom{11}{4} = \frac{11!}{4!(11-4)!} = \frac{11 \times 10 \times 9 \times 8}{4 \times 3 \times 2 \times 1} = 330 \] \[ 2^{11-4} = 2^7 = 128 \] \[ (-1)^4 = 1 \] \[ 3^4 = 81 \] ### Step 5: Combine the Values Now we can combine these values to find the constant term: \[ T_{5} = 330 \cdot 128 \cdot \frac{1}{81} \] Calculating: \[ T_{5} = \frac{330 \cdot 128}{81} \] Calculating \( 330 \cdot 128 = 42240 \): \[ T_{5} = \frac{42240}{81} \] ### Final Answer Thus, the constant term in the expansion of \( (2x^4 - \frac{1}{3x^7})^{11} \) is: \[ \frac{42240}{81} \]

To find the constant term in the expansion of \( (2x^4 - \frac{1}{3x^7})^{11} \), we will follow these steps: ### Step 1: Identify the General Term The general term \( T_{r+1} \) in the binomial expansion of \( (a + b)^n \) is given by: \[ T_{r+1} = \binom{n}{r} a^{n-r} b^r \] In our case, \( a = 2x^4 \), \( b = -\frac{1}{3x^7} \), and \( n = 11 \). Therefore, the general term becomes: ...
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