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Expand (2+ x)^(5) - (2- x)^(5) in ascend...

Expand `(2+ x)^(5) - (2- x)^(5)` in ascending powers of x and simplify your result.

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To solve the problem of expanding \((2 + x)^5 - (2 - x)^5\) in ascending powers of \(x\) and simplifying the result, we can follow these steps: ### Step 1: Expand \((2 + x)^5\) using the Binomial Theorem The Binomial Theorem states that: \[ (a + b)^n = \sum_{k=0}^{n} \binom{n}{k} a^{n-k} b^k \] In our case, \(a = 2\), \(b = x\), and \(n = 5\). So, we expand \((2 + x)^5\): \[ (2 + x)^5 = \sum_{k=0}^{5} \binom{5}{k} 2^{5-k} x^k \] Calculating each term: - For \(k = 0\): \(\binom{5}{0} 2^5 x^0 = 1 \cdot 32 \cdot 1 = 32\) - For \(k = 1\): \(\binom{5}{1} 2^4 x^1 = 5 \cdot 16 \cdot x = 80x\) - For \(k = 2\): \(\binom{5}{2} 2^3 x^2 = 10 \cdot 8 \cdot x^2 = 80x^2\) - For \(k = 3\): \(\binom{5}{3} 2^2 x^3 = 10 \cdot 4 \cdot x^3 = 40x^3\) - For \(k = 4\): \(\binom{5}{4} 2^1 x^4 = 5 \cdot 2 \cdot x^4 = 10x^4\) - For \(k = 5\): \(\binom{5}{5} 2^0 x^5 = 1 \cdot 1 \cdot x^5 = x^5\) Combining these, we have: \[ (2 + x)^5 = 32 + 80x + 80x^2 + 40x^3 + 10x^4 + x^5 \] ### Step 2: Expand \((2 - x)^5\) Using the same method, we expand \((2 - x)^5\): \[ (2 - x)^5 = \sum_{k=0}^{5} \binom{5}{k} 2^{5-k} (-x)^k \] Calculating each term: - For \(k = 0\): \(\binom{5}{0} 2^5 (-x)^0 = 32\) - For \(k = 1\): \(\binom{5}{1} 2^4 (-x)^1 = -80x\) - For \(k = 2\): \(\binom{5}{2} 2^3 (-x)^2 = 80x^2\) - For \(k = 3\): \(\binom{5}{3} 2^2 (-x)^3 = -40x^3\) - For \(k = 4\): \(\binom{5}{4} 2^1 (-x)^4 = 10x^4\) - For \(k = 5\): \(\binom{5}{5} 2^0 (-x)^5 = -x^5\) Combining these, we have: \[ (2 - x)^5 = 32 - 80x + 80x^2 - 40x^3 + 10x^4 - x^5 \] ### Step 3: Subtract the two expansions Now we need to compute: \[ (2 + x)^5 - (2 - x)^5 \] This gives: \[ (32 + 80x + 80x^2 + 40x^3 + 10x^4 + x^5) - (32 - 80x + 80x^2 - 40x^3 + 10x^4 - x^5) \] Distributing the negative sign: \[ = 32 + 80x + 80x^2 + 40x^3 + 10x^4 + x^5 - 32 + 80x - 80x^2 + 40x^3 - 10x^4 + x^5 \] ### Step 4: Combine like terms Now we combine like terms: - The constant terms: \(32 - 32 = 0\) - The \(x\) terms: \(80x + 80x = 160x\) - The \(x^2\) terms: \(80x^2 - 80x^2 = 0\) - The \(x^3\) terms: \(40x^3 + 40x^3 = 80x^3\) - The \(x^4\) terms: \(10x^4 - 10x^4 = 0\) - The \(x^5\) terms: \(x^5 + x^5 = 2x^5\) Putting it all together, we have: \[ (2 + x)^5 - (2 - x)^5 = 160x + 80x^3 + 2x^5 \] ### Final Result The final result in ascending powers of \(x\) is: \[ 2x^5 + 80x^3 + 160x \]
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ICSE-BINOMIAL THEOREM-EXERCISE 13 (a)
  1. Write out the expansions of the following: (3x-y)^(4)

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  2. Write out the expansions of the following: (3+2x^(2) )^(4)

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  3. Write out the expansions of the following: (c ) (x- (y)/(2) )^(4)

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  4. Write out the expansion of the following: (2x + (y)/(2) )^(5)

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  5. Write out the expansions of the following: (e ) (1+2x)^(7)

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  6. Write out the expansions of the following: (f) ((2)/(x) - (x)/(2) )^...

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  7. Using binomial theorem, expand [ ( x+y)^(5) + (x-y)^(5) ] and hence fi...

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  8. Expand (2+ x)^(5) - (2- x)^(5) in ascending powers of x and simplify y...

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  9. Evaluate the following: (i) (2 + sqrt(5) )^(5) + (2 - sqrt(5) )^(5) ...

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  10. If the first three terms in the expansion of (1 + ax)^(n) in ascending...

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  11. Find the first three terms in the expansion of [ 2+ x ( 3+ 4x)]^(5) in...

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  12. Expand (1+ 2 x + 3x^(2) )^(n) in a series of ascending powers of x up ...

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  13. Write down the expansion by the binomial theorem of (3x - (y)/(2) )^(4...

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  14. Using binomial theorem, evaluate : (999)^(3).

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  15. Write down in terms of x and n, the term containing x^3 in the expans...

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  16. (i) Obtain the binomial expansion of (2- sqrt(3) )^(6) in the form a+b...

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  17. Find the coefficient of x^5 in the expansion of (1 + 2x)^6 (1-x)^7.

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  18. If the coefficients of second, third and fourth terms in the expansion...

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  19. Let n be a positive integer. If the coefficients of 2nd, 3rd, 4th term...

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  20. In the binomial expansion of ( root(3) (4) + sqrt(2) )^5 find the term...

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