How do you find the seventeenth term in the arithmetic sequence for which a=4.5 and d=0.2?

1 Answer
Feb 1, 2016

seventeenth term=7.7=7.7

Explanation:

Recall the general term in an arithmetic sequence is written as:

t_n=a+(n-1)dtn=a+(n1)d

where:
t_n=tn=term number
a=a=first term
n=n=number of terms
d=d=common difference

To solve for the seventeenth term, substitute your known values into the equation:

t_n=a+(n-1)dtn=a+(n1)d

t_17=4.5+(17-1)(0.2)t17=4.5+(171)(0.2)

t_17=4.5+(16)(0.2)t17=4.5+(16)(0.2)

t_17=4.5+3.2t17=4.5+3.2

color(green)(t_17=7.7)t17=7.7

Note that the seventeenth term is also t_17=a+16dt17=a+16d. If you used this equation, it would produce the same answer:

t_17=a+16dt17=a+16d

t_17=4.5+16(0.2)t17=4.5+16(0.2)

t_17=4.5+3.2t17=4.5+3.2

color(green)(t_17=7.7)t17=7.7

:., the seventeenth term is 7.7.