Question 74355
{{{sum( ix^(i+1), i=1, n=10 )}}}
If we let i=1 and sum each consecutive ith term we get 
{{{1x^(1+1)+2x^(1+2)+3x^(3+1)}}}...{{{9x^(9+1)+10x^(10+1)}}}
{{{1x^2+2x^3+3x^4}}}...{{{9x^10+10x^11}}}
Which shows that our summation works