What is the 35th term of the arithmetic sequence where a1 = 13 and a17 = –51?

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Answer 1 · 2015-08-27T08:14:37

#color(blue)(a_35= -123#

The data given is :
#a_1=13#
#a_17=-51#

The formula for #nth# term is:
#color(blue)(a_n = a_1+(n-1)d#

Applying the same:
#a_17 = a_1+(17-1) *d #

#-51=13+ 16 d#

#16 d = -64#

#color(blue)(d=-4#

Now,
#a_35=a_1+(35-1) *d#

#=13 + 34 .(-4)#

#= 13 - 136#

#color(blue)(a_35= -123#