1、（-√1又2/3）÷√5/54

1、（-√1又2/3）÷√5/54
=（-√5/3）÷√5/54
=-√(5 /3÷5/54)
=-3√2
2、4√5÷(-5√1又4/5)
=4√5÷(-5√9/5)
=(-4/5)÷(√5/9/5)
=(-4/5)/(1/3)
=-4/3
3、√(2a²b²/c^5)÷(-√ab/2c³) (a>0,b>0,c>0)
=-√(2a²b²/c^5)÷(-ab/2c³)
=-√(4ab/c^2)
=-(2/c)√ab
4、3z√(2xy/5z²)÷3/2√5y/2x (x>0,y>0,z>0)
=2z√(2xy/5z²)÷(5y/2x )
=4/5x