=1/5+2/5 =2/9×5/12 =4×3/2×20/9 =9×9/13+9/13×1/9 =12×1/4+12×1/6-12×1/3
=3/5 =5/54 =6×20/9 =9/13（9+1/9） =3+2-4
=27/10 =82/13 =1
应用题
1+1/4=5/4
120÷5/4=96（户）
1-1/6=5/6
95÷5/6=114（人）
解方程
6x+2/3x=9 2x-3/4x=1/2 x+9/2=12
20/3x=9 2/3x=1/2 x=12-9/2
x=27/2 x=1/3 x=15/2 =1/5+2/5 =2/9×5/12 =4×3/2×20/9 =9×9/13+9/13×1/9 =12×1/4+12×1/6-12×1/3
=3/5 =5/54 =6×20/9 =9/13（9+1/9） =3+2-4
=27/10 =82/13 =1
应用题
1+1/4=5/4
120÷5/4=96（户）
1-1/6=5/6
95÷5/6=114（人）
解方程
6x+2/3x=9 2x-3/4x=1/2 x+9/2=12
20/3x=9 2/3x=1/2 x=12-9/2
x=27/2 x=1/3 x=15/2