Explanation:
first identify the common difference
The first term which i will define by u⁰=-27
u¹=u⁰+(1)d where d is the common difference and u¹ is the second term
u¹=-27+d
-11=-27+d
d=27-11=16
The 72nd term would be u⁷¹ since we started from u⁰ as our first term:
Use the explicit relation given by:
u(n)=u⁰+(n)d
u(71)=-27+71(d)
u⁷¹=-27+71(16)
u⁷¹=-27+1136
u⁷¹=1109