-234
===============
To find the 87th term in the given arithmetic sequence, we need to find the common difference first.
We are given that the first term, a₁, is 24, and the fifth term, a₅, is 12. We can use the formula for the nth term aₙ = a₁ + (n- 1)d, of an arithmetic sequence to find the common difference:
- a₅ = a₁ + 4d
- 12 = 24 + 4d
- 4d = -12
- d = -3
Now that we have the common difference, we can find the 87th term:
- a₈₇ = a₁ + 86d
- a₈₇ = 24 + 86(-3)
- a₈₇ = 24 - 258
- a₈₇ = -234
