Question

In an A.P., if Sn = n(5n + 2) , then its 5th term is
a) 47
b) 33
c) -33
d) -47​

Answer 1

Answer:

Step-by-step explanation:

d) -47​

Answer 2

Answer:

a)47

Step-by-step explanation:

Sum of 1st term=1st term

1(5×1+2)=7

Hence, first term is 7.

Sum of first 2 terms of this AP=1st term + second term

=>2(5×2+2)=7 + 2nd term

=>24=7+2nd term

=>2nd term = 7

So, we have, a=7,d=+10

5TH term = a + (n-1)d

=7 + (5-1)×10

=7+40

=47

Welcome