Question 1159112

c.

{{{sum( (-7)^(n-1), n=1,6)=(-7)^5+(-7)^4+(-7)^3+(-7)^2+(-7)^1+(-7)^0=-14706}}}

d.

 {{{sum( 3(3/2)^n, n=0,20)=3(3/2)^19+3(3/2)^18+3(3/2)^17+3(3/2)^16+3(3/2)^15+3(3/2)^14+3(3/2)^13+3(3/2)^12+3(3/2)^11+3(3/2)^10+3(3/2)^9+3(3/2)^8+3(3/2)^7+3(3/2)^6+3(3/2)^5+3(3/2)^4 +3(3/2)^3+ 3(3/2)^2+3(3/2)^1+3(3/2)^0}}}

= {{{29918.31}}}