Question

помогит епожалуйста.ооочень надо) задание во вложении

Answer 1

$sqrt{81*1.96}=sqrt{81}*sqrt{1.96}=9*1.4=12.6;$

 

$sqrt{21*15*35}=sqrt{3*7*3*5*5*7}=sqrt{3^2*5^2*7^2}=sqrt{3^2}*sqrt{5^2}*sqrt{7^2}=3*5*7=105;$

 

$frac{sqrt{343}}{sqrt{7}}=sqrt{frac{343}{7}}=sqrt{49}=sqrt{7^2}=7;$

 

$sqrt{5 frac{19}{25} 1 frac{13}{36}}=sqrt{frac{5*25+19}{25}*frac{1*36+13}{36}}=sqrt{frac{144}{25}*frac{49}{36}}=sqrt{frac{144}{25}}*sqrt{frac{49}{36}}=sqrt{(frac{12}{5})^2}*sqrt{(sqrt{frac{7}{6}})^2}=frac{12}{5}*frac{7}{6}=frac{12*7}{5*6}=frac{2*7}{5}=frac{14}{5}=2.8;$

 

$sqrt{7.2}*sqrt{0.2}=sqrt{7.2*0.2}=sqrt{36*2*0.1*2*0.1}=sqrt{6^2*2^2*0.1^2}=sqrt{6^2}*sqrt{2^2}*sqrt{0.1^2}=6*2*0.1=1.2$

 

$sqrt{frac{27^2-23^2}{2}}=\ sqrt{frac{(27-23)*(27+23)}{2}}=\ sqrt{frac{4*50}{2}}=\ sqrt{4*25}=sqrt{100}=sqrt{10^2}=10$