Question

HELP 15 POINTS

Write a rule for the nth term of the sequence. Then find a20 -
51,48,45,42

Answer 1

45 because it is what I think

Answer 2

The rule for the sequence is :
`a_(n) = 54 - 3n`. The 20th term of the sequence is -6

The nth term of an arithmetic sequence is related using the formula;

• 
  `a_(n) = a + (n-1)d`
• a = first term ; d = common difference

For the sequence given;.

• d = 48 - 51 = -3
• First term, a = 51

1.)

The rule for the nth term would be ;

`a_(n) = 51 + (n-1)-3`

`a_(n) = 51 -3n + 3`

`a_(n) = 54 -3n`

2.)

The 20th term of the sequence is:

`a_(20) = 51 + (20-1)-3`

`a_(20) = 51 + (19)-3`

`a_(20) = 51 + (-57)`

`a_(20) = 51 - 57`

`a_(20) = -6`

The 20th term of the sequence is -6