Решить уравнение 1) 9 - 4 x = 3 x - 40
2) 0,6x - 5,4 = -0,8x + 5,8
3) (5x + 8) - (8x + 14) = 9
4) 2,7 + 3y = 9(y - 2,1)​

1. 9-4х=3х-40

-4х-3х=-40-9

7х=49

х=7

2. 0.6х-5.4=-0.8х+5.8

0.6х+0.8х=5.8+5.4

1.4х=11.2

х=8

3. (5х+8)-(8х+14)=9

5х+8-8х-14=9

5х-8х=9+14

-3х=15

х=-5

4. 2.7+3у=9(у-2.1)

2.7+3у=9у-18.9

3у-9у=-18.9-2.7

-6у=-21.6

у=3.6