first one is arithmetic sequence in disguise
an=a1+d(n-1)
a1=first term
d=common differce
n=which term
so
first erm is 4
common difference is 9-4=5
an=4+5(n-1)
when n=10
4+5(10-1)
4+5(9)
4+45
49
B
3.5, to 6.5, 9.5
aritmetic, increase by 3, first term is 3.5
an=3.5+3(n-1)
10th term
3.5+3(10-1)
3.5+3(9)
3.5+27
30.5
A is49
B is 30.5
A is answer
an=a1+d(n-1)
115+(-8)(14-1)
115-8(13)
115-104
11
answer is B
an=a1+d(n-1)
45+(-3)(10-1)
45-3(9)
45-27
18
C