Question

Here are the first four terms in an arithmetic sequence.

1 4 7 10
Work out the 30th term in the sequence.

Answer 1

88

Step By Step

Explanation:

An arithmetic sequence is defined as

an=a+d(n-1) where an=nth term, a=initial term, n=term number, and d=common difference

For sequence 1,4,7... a=1 and d=4-1=7-4=3 so

an=1+3(n-1)

an=3n-2, so the 30th term is

an=3(30)-2

an=88

Answer 2

Explanation:

An arithmetic sequence is defined as

an=a+d(n-1) where an=nth term, a=initial term, n=term number, and d=common difference

For sequence 1,4,7... a=1 and d=4-1=7-4=3 so

an=1+3(n-1)

an=3n-2, so the 30th term is

an=3(30)-2

an=88