Ответ:

[tex]\frac{\sqrt{20} *\sqrt{32} }{\sqrt{10} } =\sqrt{\frac{20*32}{10} } =\sqrt{2*32} =\sqrt{64} =8[/tex]

[tex]\frac{\sqrt{35} *\sqrt{21} }{\sqrt{15} } =\sqrt{\frac{35*21}{15} }=\sqrt{\frac{7*21}{3} } =\sqrt{7*7} =\sqrt{49} =7[/tex]