4x^2-72x-225=0

4x^2-72x-225=0      this will not factor .....  using the on-site solver, we have.....

$${\mathtt{4}}{\mathtt{\,\times\,}}{{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{72}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{225}} = {\mathtt{0}} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\mathtt{\,-\,}}{\frac{\left({\mathtt{3}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{61}}}}{\mathtt{\,-\,}}{\mathtt{18}}\right)}{{\mathtt{2}}}}\\
{\mathtt{x}} = {\frac{\left({\mathtt{3}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{61}}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{18}}\right)}{{\mathtt{2}}}}\\
\end{array} \right\} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = -{\mathtt{2.715\: \!374\: \!513\: \!859\: \!981\: \!6}}\\
{\mathtt{x}} = {\mathtt{20.715\: \!374\: \!513\: \!859\: \!981\: \!6}}\\
\end{array} \right\}$$

alright lets crush this other base here

$${\mathtt{4}}{\mathtt{\,\times\,}}{{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{72}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{225}} = {\mathtt{0}}$$

first lets simplify x

$${\mathtt{4}}{\mathtt{\,\times\,}}{{\mathtt{x}}}^{{\mathtt{2}}} = {\mathtt{4}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,\times\,}}{\mathtt{4}}{\mathtt{\,\times\,}}{\mathtt{x}} = {\mathtt{16}}{\mathtt{\,\times\,}}{\mathtt{x}}$$

$${\mathtt{16}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{72}}{\mathtt{\,\times\,}}{\mathtt{x}} = {\mathtt{\,-\,}}\left({\mathtt{56}}{\mathtt{\,\times\,}}{\mathtt{x}}\right)$$

now its:

$${\mathtt{\,-\,}}{\mathtt{56}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{225}} = {\mathtt{0}}$$

add 225 to both sides:

$${\mathtt{\,-\,}}\left({\mathtt{56}}{\mathtt{\,\times\,}}{\mathtt{x}}\right) = {\mathtt{225}}$$

divide 56 both sides:

$${\mathtt{\,-\,}}{\mathtt{x}} = -{\mathtt{4.017\: \!857\: \!142\: \!857\: \!142\: \!9}}$$