1.原式=3*2/9+3*2/15-2/5
=2/3
2.原式=3/4*5/7+2/7*3/4
=3/4*(5/7+2/7)
=3/4
3.原式=1/6+4-1/8-1/6
=4-1/8
=3又8分之7
4.原式=15/28*10/3*7/50
=7/28
5.原式=32/45÷(10/15+6/15)
=32/45*15/16
=2/3
5.原式=(7-1/4)*16/9
=7*16/9-1/4*16/9
=112/9-4/9
=108/9
=12
1、3X(2/9+2/15)-0.4=3X2/9+3X2/15-2/5=2/3+2/5-2/5=2/3
2、0.75X5/7+2/7除4/3=3/4*5/7+2/7*3/4=3/4*(5/7+2/7)=3/4
3、原式=1/6+4-1/8-1/6=4-1/8=3又8分之7
4.原式=15/28*10/3*7/50=7/28
5.原式=32/45÷(10/15+6/15)=32/45*15/16=2/3
5.原式=(7-1/4)*16/9=7*16/9-1/4*16/9=112/9-4/9=108/9=12