Question

Помогите сделать 20 номер СРОЧНО!!!

Answer 1

$4sqrt{7frac{1}{2} }-frac{2sqrt{10}}{2sqrt{3}-sqrt{10}}=sqrt{frac{4*4*15}{2}}-frac{2sqrt{10}}{ sqrt{4*3}- sqrt{10}}=sqrt{120}-frac{2sqrt{10}}{ sqrt{12}- sqrt{10}}=$$frac{sqrt{120}*(sqrt{12}- sqrt{10})-2sqrt{10}}{ sqrt{12}- sqrt{10}}=frac{sqrt{120*12}-sqrt{120*10}-2sqrt{10}}{ sqrt{12}- sqrt{10}}=$$frac{sqrt{12*12*10}-sqrt{12*10*10}-2sqrt{10}}{ sqrt{12}- sqrt{10}}=frac{12sqrt{10}-10sqrt{12}-2sqrt{10}}{ sqrt{12}- sqrt{10}}=frac{10sqrt{10}-10sqrt{12}}{ sqrt{12}- sqrt{10}}=$$frac{10(sqrt{10}-sqrt{12})}{ sqrt{12}- sqrt{10}}=frac{-10(-sqrt{10}+sqrt{12})}{ sqrt{12}- sqrt{10}}=-10$