Question

Find the 87th term of the arithmetic sequence –19, -13, -7,...

Answer 1

-535

Explanation:

`a = -19\\d = T_(2) -T_(1) \\d = -19-(-13)\\d = -19+13\\d = -6\\T_(n)= a+(n-1)d \\\\T_(87) = -19+(87-1)-6\\T_(87) = -19+(86)*-6\\T_(87) = -19-516\\T_(87) = -535`

Answer 2

87th term is 497

Explanation:

first, you have to find the nth term:

figure out the difference between your set of numbers (in our case +6)

that means that is 6n. next, the nth term is basically the 0th term so you have to find the 0th term. all you have to do is do the inverse of 6n (-6n or -6), which gives us -25.

nth term= 6n-25

now replace n with 87.

final step:

87*6 (6n and n=87) and that gives you 522. then, you have to do 522-25, due to the equation. 522-25=497

497 is your 87th term.