Question

2*5√7-2*(1+2√7)+14√7/7√7-2.4*(5+10√7) =

Answer 1

$2*5 \sqrt{7} -2*(1+2\sqrt{7})+ \frac{14\sqrt{7}}{7\sqrt{7}}- \frac{24}{10}*(5+10\sqrt{7})= \\ =10\sqrt{7}-2-4\sqrt{7}+2- \frac{24}{10}*5-\frac{24}{10}*10\sqrt{7}=10\sqrt{7}-2-4\sqrt{7}+2- \\ -12-24\sqrt{7}=-18 \sqrt{7} -12=-6(3\sqrt{7} +2)$