Question

Во вложении помогите сроччно

Answer 1

$(sqrt{15}+sqrt{10})*2sqrt{5}-5sqrt{12}=sqrt{15}*2sqrt{5}+sqrt{10}*2sqrt{5}-5sqrt{12}=$

$=sqrt{3}*sqrt{5}*2sqrt{5}+sqrt{2}*sqrt{5}*2sqrt{5}-5sqrt{4}*sqrt{3}=$

$=10sqrt{3}+10sqrt{2}-10sqrt{3}=10sqrt{2}$

 

 

$frac{2sqrt{70}-2sqrt{28}}{3sqrt{35}-3sqrt{14}}=frac{2sqrt{2}sqrt{35}-2sqrt{2}sqrt{14}}{3sqrt{35}-3sqrt{14}}=frac{2sqrt{2}(sqrt{35}-sqrt{14})}{3sqrt{35}-3sqrt{14}}=frac{2sqrt{2}}{3}$

 

 

$(2sqrt{12}-3sqrt{3})^{2}=4*12-2*2sqrt{12}*3sqrt{3}+9*3=$ 

$48-12sqrt{36}+27=48-72+27=3$

 

 

$frac{10-5sqrt{3}}{10+5sqrt{3}}+frac{10+5sqrt{3}}{10-5sqrt{3}}=frac{(10-5sqrt{3})^2+(10+5sqrt{3})^2}{(10+5sqrt{3})*(10-5sqrt{3})}=$ 

$=frac{100-10sqrt{3}+75+100+10sqrt{3}+75}{100-75}=frac{350}{25}=14$