Question

Find the 10th partial sum of the summation of negative 5i plus 2, from i equals 1 to infinity.

Answer 1

Sum of {(-5i + 2) from i = 1 to 10} =

= - 5{ (Sum i) from  1 to 10} + (sum of 2) from 1 to 10

= - 5 {1 + 10)*10/2} + 2{10} =

=  -5(11)(5) + 20 = -275 + 20 = - 255