7分之4-12分之5+5又7分之3
=4/7+5又3/7-5/12
=6-5/12
=5又7/12
8分之7+5分之3-8分之3+5分之2
=7/8-3/8+3/5+2/5
=1+1/2
=1又1/2
4又8分之5-(5分之2-8分之3)
=4又5/8+3/8-2/5
=5-2/5
=4又3/5
6分之5-9分之5-9分之4+6分之1
=5/6+1/6-(5/9+4/9)
=1-1
=0
7分之4-12分之5+5又7分之3
=4/7+5又3/7-5/12
=6-5/12
=5又7/12
8分之7+5分之3-8分之3+5分之2
=7/8-3/8+3/5+2/5
=1+1/2
=1又1/2
4又8分之5-(5分之2-8分之3)
=4又5/8+3/8-2/5
=5-2/5
=4又3/5
6分之5-9分之5-9分之4+6分之1
=5/6+1/6-(5/9+4/9)
=1-1
=0