1)
a=3 [tex]\sqrt{2}[/tex] =>[tex] a= \sqrt{3*3*2}[/tex] = [tex] \sqrt{18} [/tex]
b=2 [tex]\sqrt{5}[/tex] =>[tex] b= \sqrt{2*2*5} [/tex] = [tex] \sqrt{20}[/tex]
[tex] \sqrt{20} [/tex]> [tex] \sqrt{18} [/tex] => b>a
2)
mg= [tex] \sqrt{a*b} [/tex] => mg =[tex] \sqrt{3 \sqrt{21}*7 \sqrt{21} } [/tex] =[tex] \sqrt{3*7*21} [/tex] = [tex] \sqrt{21*21} [/tex] = 21
3)
[tex]2 \sqrt{6}* (\sqrt{8} + \sqrt{18})+(3 \sqrt{15})/ (\sqrt{45}-3 \sqrt{20})
[/tex]
= [tex]2 \sqrt{6}*(2 \sqrt{2}+3 \sqrt{2})+3 \sqrt{15}/(3 \sqrt{5}-2 \sqrt{5}) [/tex]
=[tex]2 \sqrt{6}*5 \sqrt{2}+3 \sqrt{15}/ \sqrt{5} [/tex]
= [tex]10 \sqrt{12}+3 \sqrt{3[tex]
= 20 \sqrt{3} +3 \sqrt{3}
[/tex]} [/tex]
= [tex]23 \sqrt{3} [/tex]
