Question

answer me fast.....​

Answer 1

Step-by-step explanation:

3rd and 7th terms of A.P means

a+2d and a+6d respectively

Hence,

a+2d+a+6d =6(first condition)

=2a+8d =6

a=6-8d/2

a+2d(a+6d)=8(second condition)

a2 +6ad +2ad +12d2

and you can solve the other steps

thanks

Answer 2

Step-by-step explanation:

t3 + t7 = 6

2a + 8d = 6

2a =6 - 8d

a = 3 - 4d........(1)

t3. t7 = 8

(a+2d ) (a +6d) = 8

a^2 + 6ad + 2ad + 12d^2 = 8

(9 - 12ad + 36d^2) + (6ad - 24d^2 ) +

(2ad + 12d^2) = 8

24d^2 - 8ad +1 = 0

24 d^2 - 24d - 32d^2 +1 =0

-8d^2 -24d +1 =0

8d^2 +24d -1 =0

-24 +/- √576 + 32/16

-24 +/- 25/16......(√608 ~ 25)

-24 +25 /16 or -24 -25/16

1/16 or -49/16

a = 3-4d or a = 3-4d

= 3-1/4 or a = 61/4

= 11/4

required term =

a-d, a, a+d

(11/4 - 1/16) , (11/4), (11/4+1/16)

or

(61/4 + 49/16) , (61/4), (61/4 - 49/16)