Question

In the expansion of , the coefficient of x is 5. Find the value of the constant a.

Solution

We are given expression as;

Expression for the general term in the Binomial expansion of  is:

In the given case:

Hence;

Since we are looking for the terms with  i.e. we can  equate;

Now we can find the term with; Substituting ;

We are given that the coefficient of x is 5. Therefore;