Question

Срочно помогите 5 и 4 задание

Answer 1

4) 45y^2-13.5y-72y+21.6=0
45y^2-85.5y+21.6=0
D=7310,25-3888=3422,25
y1=(85.5+58.5)/90=1.6
y2=(85.5-58.5)/90=0.3