[tex]\begin{gathered} 63x^{12}-35x^6,\text{ fist we wil find the common factor of 63 and 35} \\ 63=9\cdot7 \\ 35=5\cdot7 \\ \\ \text{ Thus the greatest common factor of 35 and 63 is 7} \\ 63x^{12}-35x^6=7(9x^{12}-5x^6) \\ \text{ now we extract the minor x power !} \\ =7x^6(9x^6-5) \end{gathered}[/tex]
