Question

If the 2nd term of an AP is 2 and 7th term is 22, the sum of first 35 terms
of the AP is​

Answer 1

Step-by-step explanation:

Here it has Been given that,

T2=a+d=2—(1)

T7=a+6d=22—(2)

From equation (1)

a=2−d

Substitute this in eq (2)

2−d+6d=22

5d=22−2=20

d=4

Now substitute the value of d in eq (1)

a+d=2

a=2−d

a=2−4

a=−2

Now,

Sn=n[2a+(n−1)d]2

Here n=35

a=−2

d=4

So ,

S35=35[2(−2)+(35–1)4]2

S35=35[−4+136]2

S35=35∗132/2

S35=2310

I hope it's helpful ☺️

Answer 2

Answer:

1120

Step-by-step explanation:

a2 = 2

a7=22

a + d =2

a +6d=22

-----------------

-5d=-20

d=4

a+4=2

a=-2

S=n/2(2a+(n-1)d)

=35/2(2×-2+(35-1)2)

=35/2(-4+34×2)

=35/2×(-4+68)

=35/2×64

=2240/2

=1120

therefore sum of first 35 terms is 1120.