Question

Find the 16th term of the sequence.217 = -5, d = - 15

Answer 1

To find the 16th term, we will simply used the formula below:

`S_n=(n)/(2)\lbrack a+(n-1)d\rbrack`

where a is the first term and d is the common difference

n is the number of term

From the question,

a=-5 d=-15 and n=16

substitute the values into the formula

`S_(16)=(16)/(2)\lbrack-5+(16-1)*-15\rbrack`
`=8\lbrack-5+15(-15)\rbrack`
`=8\lbrack-5-225\rbrack`
`=8\lbrack-230\rbrack`
`=-1840`