Question

if n is a natural number then 7n_6n always end with​

Answer 1

Answer:

6

n

−5

n

For n=1

6

1

−5

1

=6−5=01

⇒ Unit digit is 1, i.e., ends with 1.

For n=2

6

2

−5

2

=36−25=1

⇒ Unit digit is 1, i.e., ends with 1.

For n=3

6

3

−5

3

=216−125=91

⇒ Unit digit is 1, i.e., ends with 1.

By continuity, we can say that (6

n

−5

n

) always ends with 1.