Question

What is the sum of the series?

Answer 1

\[\sum_{n-1}^{20}\left( 5-n \right)\]

Answer 2

-10

Answer 3

I don't have that as my answer choices..

Answer 4

\[5-1+5-2+5-3+....+5-20\]

\[20\times5\times (-1)(1+2+3+...+20)\]
\[100-\frac{ (20)(21) }{ 2 }= 100-210=-10\]

Answer 5

I see what you did, but none of them are in my answer choices..

i have these:

a,-220'
b, -110
c,-95
d,110

Answer 6

sorry .. it should b -110

Answer 7

as 100-210 is -110 not -10

Answer 8

Thankyou [; !

Answer 9

ur welcome :)