Question

the 21th rerm of an ap whose 1st two termsare -3 and 4is

a) 17
b)137
c)143
f)-143​

Answer 1

$\bold\red{Answer:}$

a=-3

d=4-(-3)=7

tn=a+(n-1)d

t21=a+20d

=-3+20(7)

=-3+140

=137

$\green{Answer=option(b)}$

hope it helps