The sum in expanded form is given by:
[tex]\sum_{k=5}^{8} x^k=x^5+x^6+x^7+x^8[/tex]
Expansion means we have to expand or enlarge the given algebraic expression by using certain operations that are involved.
We are asked to expand the summation term which is given by:
[tex]\sum_{k=5}^{8} x^k[/tex]
i.e. we have to expand this expression for each of the value of k from k=5 to k=8
Hence, we get the expansion of this finite series as:
[tex]\sum_{k=5}^{8} x^k=x^5+x^6+x^7+x^8[/tex]
