Question

for ap -3,-7,-11....can we find a30-a20 without actually finding a 30 and a20

Answer 1

HERE IS YOUR ANSWER

yes we can find

as a30 = a1 + 29d.

and
a20 = a1 + 19d

a30-a20 = 10 d ( d is the common difference = -4 )

= 10 × -4
= -40

HOPE MY ANSWER IS CORRECT