Question

(6√27-4√100)*(6√27+4√100)​

Answer 1

$\displaystyle\bf\\\boxed{(a-b)\cdot(a+b)=a^{2} -b^{2} }\\\\\\(6\sqrt{27} -4\sqrt{100})\cdot(6\sqrt{27}+4\sqrt{100})=\\\\\\=(6\sqrt{27})^{2} -(4\sqrt{100})^{2} =36\cdot 27-16\cdot 100=\\\\\\=972-1600=-628$