The sum of first 6terms of an A.P.is 6.The product of second term and fifth term is -80.Find the terms of A.P.

1 answer

(6/2)(2a+5d) = 6
(a+d)(a+4d) = -80

or,

2a+5d = 2
a^2+5ad+4d^2 = -80

Now just solve for a and d. One sequence is

-14, -8, -2, 4, 10, 16
sum = 6
(-8)(10) = -80

There is another value for a as well