Question

I need answer for all the Sums in 2nd main only

Answer 1

1.
a=6,d=2
t15=a+14d
=6+14(2)
6+28=34
2.
a=2
t20=59
a+19d=59
2+19d=59
19d=57
d=3
t32=a+31d
2+31(3)
2+93
=95
3.
a+9d=2
a+15d=-10
....................
-6d=12
d=-2
a+9(-2)=2
a-18=2
a=20
t11= a+10d
20+10(-2)
20-20=0
4.