Question

@welshfella last one I promise

Answer 1

\[\sum_{n=2}^{10}-2n-3\]

Answer 2

the -2*2-3= -7 I got that much

Answer 3

There's no difference in the method from the last 2 examples.
Just plug the values in and add them up.
This as another Arithmetic series like the first one.

Answer 4

so i'm just going up to 10 again, so (1+2+3+4+5+6+7+8+9+10) *-2*2-3??

Answer 5

yes and the next one is -2(3) - 3 = -9

Answer 6

why 3 I thought it was n=2

Answer 7

No
first you multiply the sum of 2 to 10 (not 1 to 10) by -2 then add 9*(-2) '
Its 9 because there are 9 values from 2 to 10.

Answer 8

ITs 9 * (-3)

Answer 9

so instead of 1-10 its 2-10, so basically (2+3+4+5+6+7+8+9+10)=54
then times 54*-2= -108
the take -108 and add 9*(-3) to get
-135 and that's the answer??

Answer 10

yes

Answer 11

thank you!!!! you are a lifesaver!

Answer 12

yw