Помогите решить математику Смешанные и дробные числа 1) (5.1/2*8)*(2/3*12)-3.3/5*5= 2) 4.2/3+7/15*1.1/5= 3) 2.5/8:3+2.1/4:9-3.

1)
(5.1/2*8)*(2/3*12)-3.3/5*5=334
5 1/2*8=11/2*8=44
2/3*12=8
44*8=352
3 3/5*5=18/5*5=18
352-18=334

2)
4.2/3+7/15*1.1/5=5 17/75
7/15*1 1/5=7/15*6/5=14/25
4 2/3+14/25=14/3+14/25=350/75
+42/75=392/75=5 17/75

3)
2.5/8:3+2.1/4:9-3.3/4:9=17/24
2 5/8:3=21/8*1/3=7/8
2 1/4:9=9/4*1/9=1/4
3 3/4:9=15/4*1/9=5/12
7/8+1/4=7/8+2/8=9/8
9/8-5/12=27/24-10/24=17/24

4)
2.2/12+(1.3/8-1.1/12):1.1/5-3/10:1.1/5=10 2/3
1 3/8-1 1/12=11/8-13/12=33/24-26/24=7/24
7/24:1 1/5=7/24*5/6=35/4
2 2/12+35/4=26/12+35/4=26/12+105/12=131/12
3/10:1 1/5=3/10*5/6=1/4
131/12-1/4=131/12-3/12=128/12=10 2/3