Question

sum of the third and seventh term of an ap is 6 and their product is 8 find the sum of first seven term of A. P​

Answer 1

Answer:

Step-by-step explanation:

a3+a7=6

a+2d +a +6d =6

a+ 4d=3

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

thus solving we get d=1/2

a= 1

S7=7/2(2x1 + 6(1/2))

S7= 3.5x 5

S7=17.5