根号45/根号5==根号（45/5）根号9=3根号0.76/根号0.19 =根号（0.76/0.19）=根号4=2根号3又1/5/根号1又3/5=根号15/5/根号8/5=根号(16/5 /8/5)=根号2根号32a^3b/根号2ab(a>0,b>0）=根号（32a^3b/2ab）=根号16a...