1). (1.8-0.3y)(2y+9)=0
3.6y+16.2-0.6y^2-2.7y=0
-0.6y^2+0.9y+16.2=0
D=0.81+38.88=39.69
y1,2=(-0.9+-6.3)/(-1.2)
y1=-4.5; y2=6
2). (5y+4)(1.1y-3)=0
5.5y^2-15y+4.4y-12=0
5.5y^2-10.6y-12=0
D=112.36+264=376.36
y1,2=(10.6+-19.4)/11
y1=2*8/11
y2=0.8
<span>3(у-5)-2(у-4)=8</span>