$\"\"$

The given equation is $\"\"$ .

When n = 1,

Left side of the given equation is $\"\"$ .

Right side is $\"\"$ .

Thus, the equation is true for $\"\"$ . $\"\"$

Assume $\"\"$ for a positive integer k. $\"\"$

Show that the given equation is true for $\"\"$ .

Add $\"\"$ to each side.

$\"\"$

$\"\"$ $\"\"$

Take out common factors.

$\"\"$

The last expression is the right side of the equation to be proved.

When n is replaced by k + 1.

Therefore the equation is true for n = k + 1.

The equation is true for all values of n. $\"\"$

The given statement is true for any positive integer.