Factor Special Products: example 7.50

$\begin{array}{cccc}& & & \hfill 100-h^2\hfill \\ \\ \\ \text{Is this a difference of squares? Yes.}\hfill & & & \hfill {\left(10\right)}^2-{\left(h\right)}^2\hfill \\ \\ \\ \text{Factor as the product of conjugates.}\hfill & & & \hfill \left(10-h\right)\left(10+h\right)\hfill \\ \\ \\ \text{Check by multiplying.}\hfill & & & \\ \\ \\ \left(10-h\right)\left(10+h\right)\hfill & & & \\ 100-h^2✓\hfill & & & \end{array}$

Be careful not to rewrite the original expression as $h^2-100$.

Factor $h^2-100$ on your own and then notice how the result differs from $\left(10-h\right)\left(10+h\right)$.