解1:
7分之15-(7分之8+14分之9)
=15/7-(8/7+9/14)
=15/7-8/7-9/14
=1-9/14
=5/14
解2:
7分之6+(5分之4-10分之3)
=6/7+(4/5-3/10)
=6/7+(8/10-3/10)
=6/7+1/2
=12/14+7/14
=19/14
解3:
10分之7-4分之1+10分之3-4分之3
=7/10-1/4+3/10-3/4
=7/10+3/10-(1/4+3/4)
=2/5-1
=-3/5
解4:
12分之5+(7分之6+12分之7)
=5/12+(6/7+7/12)
=5/12+7/12+6/7
=1+6/7
=13/7
解5:
8分之7-6分之1-12分之5
=7/8-1/6-5/12
=7/8-(2/12+5/12)
=7/8-7/12
=21/24-14/24
=7/24
解6:
12分之13-6分之5+24分之11
=13/12-5/6+11/24
=26/24-20/24+11/24
=(26-20+11)/24
=17/24