## anonymous one year ago medal Find the sum of the summation of 2 i minus 9, from i equals 3 to 10

1. anonymous

answer choices 52 26 13 32

2. anonymous

so u need help?

3. anonymous

there

4. anonymous

what

5. ybarrap

Is this the problem? $$\Large{ \sum_{i=3}^{10}\left ( 2i-9\right ) }$$ If so, let's rearrange indices so that i starts at zero and simplify: $$\Large{ \sum_{i=0}^{7}\left ( 2(i+3)-9\right )=\sum_{i=0}^{7}\left ( 2i+6-9\right )\\ =\sum_{i=0}^{7}\left ( 2i-3\right )=\left (2\sum_{i=0}^{7}i\right )-3\times 8 }$$ Does this make sense? Can you finish?

6. anonymous

32