2又1/4*1又3/8+2又1/4*1又5/8+2又1/4
=2又1/4*(1又3/8+1又5/8+1)
=2又1/4*4
=9
1/25*25又1/2
=1/25*(25+1/2)
=1+1/30
=1又1/30
24又1/6*1/5
=145/6*1/5
=29/6
=4又5/6