Question

please please answer this question 2a and 2c

Answer 1

(2b)

fourth term=8,sixth term=16

a4=8,a6=14

a+3d=8 ---(1)

a+5d=14 ---(2)

on sub eq (1)(2),we get

-2d=-6

d=3

common difference =3

putting the value of d=3 in eq (1),we get

a+3(3)=8

a=8-6

a=2

first term =2

sum of first 20 term=20/2*(2(2)+19(3))

=610