20 . заранее за . №1. г) (2 целых 3/7 + 1 целая 5/ целая 4/7+5/9) д) -(2, 77-7 целых 2/, 23-4 целых 7/9) е) -(5/6+1, , 87-1/3)

Г) (2³/₇ + 1⁵/₉)-(1⁴/₇+⁵/₉) = 2³/₇ + 1⁵/₉ - 1⁴/₇ - ⁵/₉ = 1⁶/₇
1) 2³/₇ - 1⁴/₇ = 1¹⁰/₇ - 1⁴/₇ = ¹⁰⁻⁴/₇ = ⁶/₇
2) 1⁵/₉ - ⁵/₉ = 1
3) 1 + ⁶/₇ = 1⁶/₇

д) -(2,77-7²/₉)-(0,23-4⁷/₉) = -²⁷⁷/₁₀₀ + 7²/₉ - ²³/₁₀₀ + 4⁷/₉ = 7
1) -²⁷⁷/₁₀₀ - ²³/₁₀₀ = - ³⁰⁰/₁₀₀ = - 3
2) 7²/₉ + 4⁷/₉ = 11²⁺⁷/₉ = 11⁹/₉ = 10
3) 10 - 3 = 7

е) -(⁵/₆+1,37)-(-2,87-¹/₃) = -⁵/₆ - ¹³⁷/₁₀₀ + ²⁸⁷/₁₀₀ + ¹/₃ = 1
1) -⁵/₆ + ¹/₃ = -⁵/₆ + ²/₆ = - ³/₆ = - ¹/₂ = - 0,5
2) -¹³⁷/₁₀₀ + ²⁸⁷/₁₀₀ = ⁻¹³⁷⁺²⁸⁷/₁₀₀ = ¹⁵⁰/₁₀₀ = 1,5
3) 1,5 - 0,5 = 1

2х+17=22+3х  
2х-3х=22-17
- х=5
х= - 5
18 + 3х=х+14
3х-х=14-18
2х= - 4
х = -2
25-4х=12-5х
-4х+5х=12-25
х=-13
13х+27=16х+4,5
13х-16х=4,5-27
-3х=-22,5
х=7,5
21х+45=17+14х
21х-14х=17-45
7х= - 28
х= - 4
13х+70=2х+15
13х-2х=15-70
11х=-55
х=-5
3х-1=2(х-2)
3х-1=2х-4
3х-2х=-4+1
х=-3
3(х+5)=7-5х
3х+15=7-5х
3х+5х=7-15
8х=-8
х=-1
19(у-9)=3(у+7)
19у-171=3у+21
19у-3у=171+21
16у=192
у=12
4(х-9)=3(х-8)
4х-36=3х-24
4х-3х=-24+36
х=12
3(2х-9)=5(х-4)
6х-27=5х-20
6х-5х=-20+27
х=7
7(3-2х)=15(1-х)
21-14х=15-15х
-14х+15х=15-21
х=-6
7х-(3+2х)=х+9

7х-3-2х=х+9

5х-х=9+3

4х=12

х=3

13-(2х-5)=х-3

13-2х+5=х-3

-2х-х=-3-5-13

-3х=-21

х=7

3х-(10-9х)-22х - условие написано неверно

3х-10+9х-22х

-10-10х;

26-(17-2х)=5х

26-17+2х=5х

9=5х-3х

2х=9
х=4,5

2х+17=22+3х  
2х-3х=22-17
- х=5
х= - 5
18 + 3х=х+14
3х-х=14-18
2х= - 4
х = -2
25-4х=12-5х
-4х+5х=12-25
х=-13
13х+27=16х+4,5
13х-16х=4,5-27
-3х=-22,5
х=7,5
21х+45=17+14х
21х-14х=17-45
7х= - 28
х= - 4
13х+70=2х+15
13х-2х=15-70
11х=-55
х=-5
3х-1=2(х-2)
3х-1=2х-4
3х-2х=-4+1
х=-3
3(х+5)=7-5х
3х+15=7-5х
3х+5х=7-15
8х=-8
х=-1
19(у-9)=3(у+7)
19у-171=3у+21
19у-3у=171+21
16у=192
у=12
4(х-9)=3(х-8)
4х-36=3х-24
4х-3х=-24+36
х=12
3(2х-9)=5(х-4)
6х-27=5х-20
6х-5х=-20+27
х=7
7(3-2х)=15(1-х)
21-14х=15-15х
-14х+15х=15-21
х=-6
7х-(3+2х)=х+9

7х-3-2х=х+9

5х-х=9+3

4х=12

х=3

13-(2х-5)=х-3

13-2х+5=х-3

-2х-х=-3-5-13

-3х=-21

х=7

3х-(10-9х)-22х - условие написано неверно

3х-10+9х-22х

-10-10х;

26-(17-2х)=5х

26-17+2х=5х

9=5х-3х

2х=9
х=4,5