Question

What is the product of 7√​20 and 10√6​​ ?

Answer 1

$\bf 7\sqrt{20}\cdot 10\sqrt{6}\implies (7)(10)\sqrt{(20)(6)}\implies 70\sqrt{120} \\\\\\ 70\sqrt{4\cdot 30}\implies 70\sqrt{2^2\cdot 30}\implies 140\sqrt{30}$