Question

Find an equation for the nth term of the arithmetic sequence.

a18 = 97, a20 = 281

Answer 1

an = -1467 - 92(n + 1)

an = -1467 + 92(n + 1)

an = -1467 + 92(n - 1)

an = -1467 + 92(n - 2)
like how do i fine ninth term and all that

Answer 2

a20-a18=a1+19d-a1-17d=2d =281-97
so
d=92

Answer 3

can you go on ?

Answer 4

uhh im confused

Answer 5

an=a1+(n-1)d
you know that ?

Answer 6

yeah, so im plugging that equation into the answer

Answer 7

a18=a1+17d =97
a20=a1+19d=281
solve the system of equation

Answer 8

where are you getting the 17d and the 19d from

Answer 9

a20-a18 =2d
a20 - a18=281-97
so 2d =281-97=184
d=92

Answer 10

now find a1

a18 = a1+17 (92) =97
so
a1=97 - 17(92)=-1467

Answer 11

can you go on ?

Answer 12

so is it D

Answer 13

an = -1467 + 92(n - 2)

Answer 14

no a(n)=a1+(n-1)d
so
an=-1467+92(n-1)

Answer 15

understand ?

Answer 16

yeah thnx