4分之1除以(3-13分之5-13分之8)
=1/4÷(3-13/13)
=1/4÷2
=1/8
5/12*(4/15+2/5)-3/5
=5/12*4/15+5/12*2/5-3/5
=1/9+1/6-3/5
=15/54-3/5
=(75-162)/270
=-29/90
4分之1除以(3-13分之5-13分之8)
=1/4÷(3-13/13)
=1/4÷2
=1/8
5/12*(4/15+2/5)-3/5
=5/12*4/15+5/12*2/5-3/5
=1/9+1/6-3/5
=15/54-3/5
=(75-162)/270
=-29/90