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If 23\xa0+43+63+............+(2n)3\xa0=kn2(n+1)2, then k=? |
| Answer» The sum of cubes of even numbers is equal to 2 n^2 (n+1)^2So 2^3+ 4^3+ 6^3 +........+2n^2 = 2n^2(n+1)^2\xa02 n^2 (n+1)^2 = k n^2 (n+1) ^2Cancelling the common terms, we get\xa0k=2 | |