there are 8 terms from the 3rd to the 11th, so
8d = -7-9 = -16
so, d = -2
Now you can find a, and then a+4d.
The third term of an Ap is 9 while 11th term is -7 find the first 5th term of the Ap
4 answers
The sum of the 16 term
Maths
Work