1.(5,8/9 : 1, 17/36+1,1/4)•5/21

2.(2 1/4 + 4, 5/6): 3, 2/5 - 3/4 : 3/5

3.( 3,1/4 + 3 5/6): (4, 2/3-1,1/8)

4. (6 4/5 - 2 3/4): (2 16/21 + 3 2/3)

5. (2 3/8 + 3 7/24): (4 2/3 - 1 1/8)

6.(1 3/4 + 2 1/3): (7 1/2 - 1 2/3)

7.(4/5 + 4/7): (3 3/8 + 2 11/4)

8.(3,6 - 1, 2/3): (4 1/15 - 2,7/9)

9. (4, 1/6*(1 1/2 - 3/5) + (3/4 + 5/6)*6

Пошаговое объяснение:

1. (5 8/9 ÷1 17/36 +1 1/4)•5/21=(53/9 ·36/53 +1 1/4)·5/21=(4+1 1/4)·5/21=5 1/4 ·5/21=21/4 ·5/21=5/4=1 1/4=1,25

2. (2 1/4 +4 5/6) ÷3 2/5 -3/4÷3/5=(2 3/12 +4 10/12)·5/17 -3/4 ·5/3=6 13/12 ·5/17 -5/4=85/12 ·5/17 -5/4=(5·5)/12 -5/4=25/12 -15/12=10/12=5/6

3. ( 3 1/4 +3 5/6)÷(4 2/3 -1 1/8)=(3 3/12 +3 10/12)÷(4 16/24 -1 3/24)=6 13/12 ÷3 13/24=85/12 ·24/85=2

4. (6 4/5 -2 3/4)÷(2 16/21 +3 2/3)=(6 16/20 -2 15/20)÷(2 16/21 +3 14/21)=4 1/20 ÷5 30/21=81/20 ÷5 10/7=81/20 ·7/45=567/900=63/100=0,63

5. (2 3/8 +3 7/24)÷(4 2/3 -1 1/8)=(2 9/24 +3 7/24)÷(4 16/24 -1 3/24)=5 16/24 ÷3 13/24=5 2/3 ·24/85=17/3 ·24/85=8/5=1 3/5=1,6

6. (1 3/4 +2 1/3)÷(7 1/2 -1 2/3)=(1 9/12 +2 4/12)÷(7 3/6 -1 4/6)=3 13/12 ÷(45/6 -10/6)=49/12 ÷35/6=49/12 ·6/35=7/(2·5)=7/10=0,7

7. (4/5 +4/7)÷(3 3/8 +2 11/4)=(28/35 +20/35)÷(3 3/8 +2 22/8)=48/35 ÷5 25/8=48/35 ·8/65=384/2275

8. (3,6 -1 2/3)÷(4 1/15 -2 7/9)=(3 2/5 -1 2/3)÷(4 3/45 -2 35/45)=(3 6/15 -1 10/15)÷(3 48/45 -2 35/45)=(51/15 -25/15)÷(1 13/45)=26/15 ·45/58=(13·3)/29=39/29=1 10/29

9. 4 1/6 ·(1 1/2 -3/5)+(3/4 +5/6)·6=25/6 ·(1,5-0,6)+(9/12 +10/12)·6=25/6 ·0,9 +19/12 ·6=25/6 ·9/10 +19/2=(5·3)/(2·2) +9 1/2=15/4 +9,5=3,75 +9,5=13,25