the value of sigma r(0 to 10) of 10Cr x 3^r x (-2)^10-r is
 

Dear student, 
​​​​​​$$\begin{gathered} we have , \\ \sum _{r=0}^{r=10}{10}_{C_r}{3}^r(-2{)}^{10-r}, This is the general term written for the expansion \\ of (3-2{)}^{10}=1^{10}=1 \end{gathered}$$
Hope this clears your doubt 
With regards