Question

determine the coefficient of x^5 in the expression
(2x-3)^8

help pls!!

Answer 1

going with binomial theorem\[(a+b)^n=\sum_{k=0}^{n} \binom{n}{k} a^k b^{n-k}\]and setting a=2x ,b=-3 and n=8 ... will be your start point

Answer 2

\[\sum_{k=0}^{8} \left(\begin{matrix}8 \\ 5\end{matrix}\right) 2^5 (-3) ^3 x^5\]
Is this is?

Answer 3

u just need to evaluate one term of the sum and its where k equals to 5 so just
\[ \left(\begin{matrix}8 \\ 5\end{matrix}\right) 2^5 (-3) ^3 x^5\]