Question

Help Please?
Write an expression to describe a rule for the sequence. Then find the 100th term in the sequence.
5. –4, 1, 6, 11, 16, . . . (1 point)

a. –10n + 6; –994
b. 5n – 9; 491
c. 6n – 10; 590
d. –9n + 5; –895

6. 3, 7, 11, 15, 19, 23, . . . (1 point)

a. 2n + 1; 201
b. n + 4; 104
c. n + 4; 403
d. 4n – 1; 399

Answer 1

well...
regarding to the first one:
as much as I see it is arithmetic sequence:
use:
\[\LARGE a_n=a_1+(n-1)d\]
you have:
\[\LARGE d=a_n-a_{n-1}\]
\[\LARGE d=a_2-a_1\]
\[\LARGE d=1-(-4)\]
\[\LARGE d=5\]
so:
\[\LARGE a_{100}=a_1+(100-1)d\]
\[\LARGE a_{100}=-4+99\cdot 5 \]
\[\LARGE a_{100}=-4+495 \]
\[\LARGE a_{100}=491 \]

on the second sequence you have arithmetic sequence too... use these steps , and there you go :)