(4.5y+9)-(6.2-3.1y)=7.2y+2.8

ответ о(4,5у+9)-(6,2-3,1у)=7,2у+2,84,5у+9-6,2+3,1у=7,2у+2,84,5у+3,1у-7,2у=2,8-9+6,20,4у=0у=0:0,4у=0

1.4y-7.2y=2.8-2.8-5.8y=0y=0