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Please verify that your equation is the following:

$\frac{sin(x)cos(x) + sin(x)}{cos(x) + cos^2(x)} = tan(x)$

If so, the answer depends on factoring the top half and the bottom half of the fraction side of the equation and on a quotient identity.

First, factor the top portion of the fraction:
$\frac{sin(x)(cos(x) + 1)}{cos(x) + cos^2(x)} = tan(x)$

Second, factor the bottom portion of the fraction:
$\frac{sin(x)(cos(x) + 1)}{cos(x)(1 + cos(x))} = tan(x)$

Now you can see how the top and bottom partially cancel:
$\frac{sin(x)(cos(x) + 1)}{cos(x)(1 + cos(x))} = \frac{sin(x)}{cos(x)} * \frac{1 + cos(x)}{1 + cos(x)} = \frac{sin(x)}{cos(x)} * 1 = \frac{sin(x)}{cos(x)}$

The quotient identity verifies that sin/cos=tan through right angle trig...

Good luck, and if something is not clear please post back with any questions.