Question

12 Σ n=3 (-5n -1) can someone help me solve?
a) -410
b)-385
c) 385
d) 410

Answer 1

i have a calculator that gives me the answer...but lets work it out ok\[\sum_{n=3}^{12}(-5x-1)\]

Answer 2

I have solved others like it but i think the -x through me

Answer 3

error that shd be n" not x so -5n-1

Answer 4

Okay, i was told to rewrite -5n-1 starting at 3 until i get to 12

Answer 5

ok i dont really know how to explain this ...look here it have all the steps
https://www.symbolab.com/solver/trigonometric-equation-calculator/%5Csum_%7Bn%3D3%7D%5E%7B12%7D%5Cleft(-5n-1%5Cright)%20/?origin=enterkey

Answer 6

Thank you for your help, i got the correct answer :)