The sum of the first n terms of an AP is 5x² + 3n. Find its 20th term.
Answers
Answered by
1
Answer:
Actually the ques should be 5n^2+3n
Answered by
0
Answer:
198
Step-by-step explanation:
sum of first two tern - sum of first term = value of second term
:: 5x (2x2)+ 3x2 - 3 x2 - 5x1+3x1
= 26-8
=18
first term= 8 =a
second term= 18
common difference= 10= d
n term = a + ( n-1) d
20 term= 8 + (20 -1)10
= 8+190
=198
Similar questions