15分之4*0.25*4
=4/15×1
=4/15
42又15分之7/7
=42÷7+7/15÷7
=6+1/15
=6又15分之1
0.5+1又4分之3
=2/4+1+3/4
=2又4分之1
(6又2分之1-2又8分之3)/2又4分之3
=33/8 ×4/11
=3/2