Question 952846
-1+8-27+64-125
<pre>
-1 = (-1)<sup>1</sup>1<sup>3</sup>

+8 = (-1)<sup>2</sup>2<sup>3</sup>

-27 = (-1)<sup>3</sup>3<sup>3</sup>

+64 = (-1)<sup>4</sup>4<sup>3</sup>

-125 = (-1)<sup>5</sup>5<sup>3</sup>

So the kth term is

(-1)<sup>k</sup>k<sup>3</sup>

And the sum is

{{{sum(((-1)^k*k^3),matrix(1,2,"",k=1),matrix(1,3,"","",5))}}}

Edwin</pre>