Question

in an a.p. s3=6, s6=3, then it's common difference is​

Answer 1

I hope you understand...

Answer 2

Sn=n/2{2a+(n-1)d}

According to the question,

6=3/2{2a+(3-1)d}

12=3(2a+2d)

4=2a+2d. Divided by 2

a+d=4

a=4-d

3=6/2{2a+(6-1)d}

3=3(2a+5d)

1=2a+5d

1=2(4-d)+5d

1=8-2d +5d

1=8+3d

8+3d=1

3d=1-8

3d= - 7

d=-7/3