Question

What is the sigma of -2+6-18+54

Answer 1

`\bf \begin{array}c -2\cdot (-3)^0&-2\cdot (-3)^1&-2\cdot (-3)^2&-2\cdot (-3)^3\\&&&\\ \cline{1-4} &&&\\ -2&6&-18&54 \end{array}~\hfill \displaystyle\sum\limits_(i=0)^(3)~-2(-3)^i`