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

1. LynFran

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

2. anonymous

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

3. LynFran

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

4. anonymous

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

5. LynFran

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

6. anonymous