The least value of nn for which the number of integral terms in the Binomial expansion of (73+113)n(\sqrt[3]{7} + \sqrt[3]{11})^n is 183, is:

Answer: 546

Step-by-step solution

Step 1: Identify the general term

The general term in the binomial expansion of (a+b)n(a+b)^n is given by Tr+1=(nr)an−rbrT_{r+1} = \binom{n}{r} a^{n-r} b^r. In this problem, a=71/3a = 7^{1/3} and b=111/3b = 11^{1/3}. We substitute these values into the general term formula.

Step 2: Determine conditions for integral terms

For the term Tr+1T_{r+1} to be an integer, the powers of 7 and 11 must be integers. This means that (n−r)(n-r) must be a multiple of 3, and rr must also be a multiple of 3. Since rr is a multiple of 3, n−rn-r being a multiple of 3 implies that nn must also be a multiple of 3.

Step 3: Express r in terms of k

Since rr must be a multiple of 3, we can write r=3kr = 3k for some integer kk. The possible values for rr range from 00 to nn. Therefore, 0≤3k≤n0 \le 3k \le n, which implies 0≤k≤n/30 \le k \le n/3.

Step 4: Calculate the number of integral terms

The number of integral terms is equal to the number of possible values for kk. Since kk ranges from 00 to ⌊n/3⌋\lfloor n/3 \rfloor, the total number of values for kk is ⌊n/3⌋+1\lfloor n/3 \rfloor + 1. We are given that the number of integral terms is 183.

Step 5: Solve for n

We set the expression for the number of integral terms equal to 183 and solve for nn. From the definition of the floor function, if ⌊x⌋=m\lfloor x \rfloor = m, then m≤x<m+1m \le x < m+1.

Step 6: Determine the range for n and find the least value

Multiplying the inequality by 3, we find the range for nn. Since nn must be a multiple of 3 (as established in Step 2), the possible values for nn are 546. The least value of nn in this range that is a multiple of 3 is 546.

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