Question

Can someone answer this for me please and thank you

Answer 1

We see that terms in given sequence decreases by 5 continuously so that means this is an arithmetic progression (AP)

so we will use nth term formula of AP to find the a27

`a_n=a_1+(n-1)d`

n=27 because we need a27

a1= first term = 15

d = common difference = 10-15=-5

Now plug these values into formula
`a_n=a_1+(n-1)d`

`a_(27)=15+(27-1)(-5)`

`a_(27)=15+(26)(-5)`

`a_(27)=15-130`

`a_(27)=-115`

So the final answer is
`a_(27)=-115`