Question

First question help. How do i change this to summation series? 49+47+45+.. for 15 terms?

Answer 1

So you need to find the n'th term of that series.
Do you see any pattern in that series ?

Answer 2

-2 :)

Answer 3

good!
thats you common difference
d= - 2

use the general formula for the n'th term of arithmetic sequence
\(\large a_n = a_1 +(n-1)d\)
a1 = 1st term = 49 here :)

Answer 4

So it would be 49+(n-1)-2?

Answer 5

careful with brackets !

49 + (n-1)(-2)
and yes, simplify this...

Answer 6

so would it be 51-2n?

Answer 7

thats correct!
\(\Large \sum \limits_{n=1}^{15}51-2n\)

Answer 8

@hartnn thanks so muchh

Answer 9

welcome ^_^
and since you're new here,
\(\Huge \mathcal{\text{Welcome To OpenStudy}\ddot\smile} \)