0.316-3y=4.5-0.8(y-9)
0,316-3y=4.5-0.8y+7.2 - 3y+0.8y=4.5+7.2-0.316 - 2.2y=11.384 y= -11 48/125:2 1/5 y= - 1423/125*5/11 y= - 1423/275 y= - 5 48/275