5,7а-8-а=6,7а-8 7-8b-9b=7-17b 15c+3-2.9c=12.1c+3 5a-(0.7a+8)=5a-0.7a-8=4.3a-8 9.6b+(7-0.4b)=9.6b+7-0.4b=9.2b+7 -5c+(13-6c)=-5c+13-6c=13-11c 5*(4-3x)+8x=20-15x+8x=20-7x (2y+5)*4-11y=8y+20-11y=20-3y 6x-3(x-7)=6x-3x+21=3x+21