16分之1減25分之1的平方根是幾?
=根號下[(1/4)²- （1/5)² ]
=根號下[(1/4+1/5)(1/4-1/5)]
=根號下(9/20)(1/20)
=根號下(9/400)
=3/20
16分之1-25分之1
=(1/4)²- （1/5)²
=(1/4+1/5)(1/4-1/5)
=(9/20)(1/20)
=9/400