Question

Find the sum of the following AP 2,7,12,...,to10 terms

Answer 1

Answer:

Step-by-step explanation:

a=2

d=7-2=5

n=10

So. Sn=n/2 (2a+(n-1)d)

=10/2 (2×2+(10-1)5)

=5 (4+45)

=5×49=245

Answer 2

Sn=n/2[2a+(n-1)d]
S10=10/2[2(2)+9(5)]
=5[4+45]
=5(49)
S10=245