Respuesta :
77, 71, 65, 59, 53, ....
what is the 23rd term
we have
a1=77
a2=71
a3=65
a4=59
a5=53
so
a2-a1=71-77=-6
a3-a2=65-71=-6
a4-a3=59-65=-6
therefore
Is an aritnetic sequence
the common difference is d=-6
the nerela expression is
an=a1+d(n-1)
substitute the given values
an=77-6(n-1)
For n=23
substitute
a_23=77-6(23-1)
a_23=77-6(22)
a_23=77-132
