Question

What is the value of the 24th term in the following arithmetic sequence?

-9, -2, 5, 12, ...

A. -170
B. 152
C. -200
D. 170

Answer 1

a=-9

d=-2-(-9)

= 7

d= 5-(-2)

= 5+2

=7

a24 = a+23d

= -9 + 23×7

= -9 + 161

a24 = 152

so, answer is b.152

hope it will help you.

Answer 2

Option B

Explanation:

`a_(n)=a_(1) +d(n-1)\\a_(n)=-9 +7(n-1)\\a_(24)=-9 +7(24-1)\\a_(24)=-9 +7(23)\\a_(24)=-9 + (161)\\\\a_(24)=152\\`