if you have 12m to the 7th power divided by 3m squared, what will you get

12m to the 7th power divided by 3m squared

$$\dfrac {(12m)^7}{(3m)^2}=\\\\
=\dfrac{12*12*12*12*12*12*12*m*m*m*m*m*\not{m}*\not{m}}{3*3*\not{m}*\not{m}}\\\\
=\dfrac{12*12*12*12*12*12*12*m*m*m*m*m}{3*3}\\\\
=\dfrac{12*12*12*12*12*\not{3}*4*\not{3}*4*m*m*m*m*m}{\not{3}*\not{3}}\\\\
=\dfrac{12*12*12*12*12*4*4*m*m*m*m*m}{1}\\$$

$$=12^5*4^2*m^5$$         |           $${{\mathtt{12}}}^{{\mathtt{5}}}{\mathtt{\,\times\,}}{{\mathtt{4}}}^{{\mathtt{2}}} = {\mathtt{3\,981\,312}}$$

$$\dfrac {(12m)^7}{(3m)^2}=3\;981\;312\;m^5$$

Is this what you mean? You really need to use brackets to make your meaning clear.

$$(12m)^7\div (3m)^2\\\\
=12^7m^7\div 3^2m^2\\\\
=(12^7\div 9)m^{7-2}\\\\
=(12^7\div 9)m^5\\\\$$

$${\frac{{{\mathtt{12}}}^{{\mathtt{7}}}}{{\mathtt{9}}}} = {\mathtt{3\,981\,312}}$$

$$\\
=3981312m^5$$