MrRobin1 Решение
5y² + 9y - 2 = 0
D = 81 + 4*5*2 = 121
y1 = (- 9 - 11)/10
y1 = - 2
y2 = (- 9 + 11)/10
y2 = 1/5

rubilovalex 5y^2-9y-2=0; D=(-9)^2-4*5*(-2)=81+40=121; y1=(9-11)/10, y2=(9+11)/10. y1= -1/5, y2=2. 5y^2-9y-2=5*(y+1/5)*(y-2)=(5y+1)*(y-2).