Verified answer

5,7а-8-а=4,7а-8

7-3,8в-9в=7-12,8в

15с+3-2,9с=12,1с+3

5(4-3х)+8х=20-15х+8х=20-7х

(2у+5)*4-11у=8у+20-11у=20-3у

6х-3(х-7)=6х-3х+21=3х+21

4,7а-8

7-12,8в

12,1с+3

20-15x+8x=20-7x

8у+20-11у=-3у+20 либо 20-3у

6x-3x-21=3x-21