Question

for an AP S4-S3=3d?​

Answer 1

Answer:

s4=4/2{2a+3d}=2{2a+3d}=4a+6d (i)

s3=3/2{2a+2d}=3/2×2{a+d}=3a+3d (ii)

(i)×3-(ii)×4

12a+18d

12a+12d

(-)

________

6d