The binomial expansion of , where n is a positive integer, in ascending power of x, is . Find the value of n and of k.

In the expansion of in the ascending power of , the coefficient of the third term is 121. Find the value of n.

Find, in ascending powers of x, the first four terms in the expansion of . Things to note: Expansion by binomial theorem is all about pattern recognition. Note that the numbers in light blue are in ascending or descending down the expansion.