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