Question

Find the third term of an arithmetic series if S3=30 & S2=15

Answer 1

I think it is clear and helpful

Answer 2

Answer:

Step-by-step explanation: since s3 is the sum of first and 2nd term so A1+A2=S2

Similarly it follows in S3 also so S3 =A1+ A2+ A3

After making equation and substitution we have A3=15

Since because a= 5and d=5