Question

Determine an AP whose 3rd term is 6th and 7th : 13 & 10​

Answer 1

Answer:

28,25,22,19,16,13,10

Step-by-step explanation:

tn= a+(n-1)d

13 = a+(6-1)d

10= a+(7-1)d

using both calculate d and a

13 = a+5d

10 =a+6d

using first

a= 13-5d

10 = 13-5d+6d

-3 = d

using value of d find a

a+5(-3)=13

a=28