Question

ncr+2.ncr-1+ncr-2=n+2cr​

Answer 1

Answer:

L.H. S. =

n

C

r

+

n

C

r−1

+

n

C

r−1

+

n

C

r−2

=

n+1

C

r

+

n+1

C

r−1

=

n+2

C

r

.

this answer is correct

mark it Braillent