Question

Find the 9th term of the arithmetic sequence.
a7 = -42 and a11 = -28; a9 = ____.

Answer 1

find the distance from a7 to a11; and divide it by how many steps it takes to get from a7 to a11

Answer 2

it takes 14 units to get from -42 to -28

Answer 3

a7 = -42
a8 = -42 + n
a9 = -42 + n + n
a10 = -42 + n + n + n
a11 = -42 + n + n + n +n = -28

-42 +4n = -28

4n = -28 +42

n = 14/4 if I see it right

Answer 4

a9 = -42 +2(14/4)
a9 = -42 +14/2
a9 = -42 + 7

a9 = -35

Answer 5

Find the 8th term of the arithmetic sequence:
3, 8, 13, 18, ...?

Answer 6

a11=a7+(11-7)*d <=>-28 = -42 +5d <=> d=7/2
a9 = a7 +(9-7)*d = -42 + 2*7/2 = -35

Answer 7

a1=3
a2=3+5 = 8
a3=3+2(5) = 13
an=3+(n-1)(5)

a8 = 3 + 7(5) = 38

Answer 8

can you please check my other one please you soo helpful