1、4/5÷1/5÷1/5÷1/5
=4/5×5×5×5
=100
2、(1/3+1/5)×15
=1/3×15+1/5×15
=5+3
=8
3、(1/2×1/6+5/12)÷1/2
=(1/12+5/12)÷1/2
=2
4、7/9÷11/5+2/9×5/11
=7/9×5/11+2/9×5/11
=(7/9+2/9)×5/11
=5/11
5、(11/12+1/4-2/3)÷1/12
=11/12×12+1/4×12-2/3×12
=11+3-8
=6
1、4/5÷1/5÷1/5÷1/5
=4/5×5×5×5
=100
2、(1/3+1/5)×15
=1/3×15+1/5×15
=5+3
=8
3、(1/2×1/6+5/12)÷1/2
=(1/12+5/12)÷1/2
=2
4、7/9÷11/5+2/9×5/11
=7/9×5/11+2/9×5/11
=(7/9+2/9)×5/11
=5/11
5、(11/12+1/4-2/3)÷1/12
=11/12×12+1/4×12-2/3×12
=11+3-8
=6