根号2又64分之41+根号下0.81*36+2/1根号下0.25 (把2/1读作二分之一,用1/2表示）
=根号（169/64)+根号下(81*36/100)+1/2根号下(1/4)
=13/8+(9*6/10)+1/2*1/2
=13/8+27/5+2/8
=15/8+27/5
=281/40