Step 1: \ \
\The statement is is divisible by
. \ \
Condition I:
\First show that, the above statement is true, when .
\ \
\ \
is divisible by
. \ \
The statement is true for .
Condition I of the Principle of Mathematical Induction holds. \ \
\Step 2:
\Condition II :
\Assume that is divisible by
.holds for some
, and determine whether the formula then holds for
. \ \
Assume that, is divisible by
for some
-----> equation (1). \ \
Now need show that, is divisible by
. \ \
\ \
\ \
is divisible by
and
is divisible by
. \ \
Therefore, is divisible by
. \ \
Thus, Condition II also holds.
\The statement is true for all natural numbers. \ \
\Solution:
\The statement is true for all natural numbers. \ \