# Find A30 − A20 For the A.P. −9, −14, −19, −24, ... - Mathematics

Find a30 − a20 for the A.P.

−9, −14, −19, −24, ...

#### Solution

In this problem, we are given different A.P. and we need to find a_30 - a_20.

A.P. −9, −14, −19, −24, ...

Here

First term (a) = -9

Common difference of the A.P. (d) = - 14 - (-9)

= -14 + 9

= -5

Now as we know

a_n = a + (n -1)d

Here we find a_30 and a_20

So for 30 th term

a_30 = a + (20 - 1)d

= -9 + (19)(-5)

= -9 - 95

= -104

So

a_30 - a_20 = -154 - (-104)

=-154 + 104

= -50

Therefore for the given A.P a_30 - a_20 = -50

Is there an error in this question or solution?

#### APPEARS IN

RD Sharma Class 10 Maths
Chapter 5 Arithmetic Progression
Exercise 5.4 | Q 20.1 | Page 25