How do you write a rule for the nth term of the arithmetic sequence given d=-3, #a_2=18#?
1 Answer
Nov 26, 2017
Explanation:
#"the nth term of an arithmetic sequence is"#
#•color(white)(x)a_n=a+(n-1)d#
#"where a is the first term and d the common difference"#
#"we have to find a"#
#a_2=a+d=18#
#rArra-3=18rArra=21#
#rArra_n=21-3(n-1)#
#color(white)(rArra_n)=21-3n+3#
#rArra_n=24-3n#
