Question

What is the common difference of an A.P. in which एक अंकगणित लड़ी का साझा अंतर क्या है, जिसमें *



15

12

9

21​

Answer 1

Answer:

Here, The common difference is 21.

Step-by-step explanation:

Here, As per our given question,

=a10-a8=42

As we know, a10=a+9d

=a8=a+7d

Now,=a+9d-(a+7d)=42

=a+9d-a-7d=42

=2d=42

=d=42/2

=d=21

So, The common difference of the given A.P. =21.

Thank you.

Answer 2

21

Step-by-step explanation:

21 is right ans ( cract ans is 4)