1) 18*5/81-2/3=4/9
1. 18*5/81= 1 1/9
2. 1 1/9 -2/3= 4/9
2) -1/4*8/6-7/18 *9/21= - 1/2
1. -1/4*8/6= - 1/3
2. 7/18*9/21=1/6
3. -1/3-1/6= - 1/2
3)11/15-7/6*8/35=
1. 11/15-7/6 = -13/30
2. -1 9/10*8/35= -76/175
Надеюсь
1) 18*5/81-2/3=4/9
1. 18*5/81= 1 1/9
2. 1 1/9 -2/3= 4/9
2) -1/4*8/6-7/18 *9/21= - 1/2
1. -1/4*8/6= - 1/3
2. 7/18*9/21=1/6
3. -1/3-1/6= - 1/2
3)11/15-7/6*8/35=
1. 11/15-7/6 = -13/30
2. -1 9/10*8/35= -76/175
Надеюсь