Question

pls solve this question ​

Answer 1

Answer:

210

Step-by-step explanation:

Solution is in the attachment

Answer 2

Answer:

Step-by-step explanation:

S14=1050

a=10

a21=?

S14=14/2(2a+l)

1050=7(20+l)

1050=140+7l

1050-140=7l

910/7=l

130=l

L=a+(n-1)d

130=10(14-1)d

130=130d

D=1

A21=a+20d

=10+20

A21=30