Question

Помогите пожалуйста :(

Answer 1

№4.

1) $2sqrt{3}+5sqrt{12}-3sqrt{27}=2sqrt{3}+5sqrt{4}sqrt{3}-3sqrt{9}sqrt{3}==2sqrt{3}+10sqrt{3}-9sqrt{3}=3sqrt{3}$

2)

$(sqrt{32}-sqrt{8})sqrt{2}=sqrt{32}sqrt{2}-sqrt{8}sqrt{2}=sqrt{64}-sqrt{16}=6-4=2$

3)

$(sqrt{5}-2)^2=(sqrt{5})^2+2*sqrt{5}*2+2^2=5+4+4sqrt{5}=4sqrt{5}+9$

4)

$(sqrt{6}+4sqrt{3})(sqrt{6}-4sqrt{3})=(sqrt{6})^2-(4sqrt{3})^2=6-16*3=6-48=-42$

№5

1) $3sqrt{7}=sqrt{9}sqrt{7}=sqrt{63}\4sqrt{6}=sqrt{16}sqrt{6}=sqrt{96}\63<96;sqrt{63}<sqrt{96}\3sqrt{7}<4sqrt{6}$

2)

$5sqrt{frac{7}{5}}=sqrt{25*frac{7}{5}}=sqrt{35}\frac{1}{2} sqrt{140}=sqrt{frac{140}{4} }=sqrt{35}\5sqrt{frac{7}{5}}=frac{1}{2} sqrt{140}$

Answer 2

спасибо))