0, 5y^3 - 0, 5 y( y+1)(y-3)=7

Question

0, 5y^3 - 0, 5 y( y+1)(y-3)=7

Answer 1

0,5^3-0,5y(y+1)(y-3)=7

0,5y^3-0,5y(y^2-3y+y-3)=7

0,5y^3-0,5y(y^2-2y-3)=7

0,5y^3-0,5y^3+y^2+1,5y-7=0

y^2+1,5y-7=0

D=2,25+28=30,25

y1=(-1,5+5,5) / 2 = -3,5

y2=(-1,5-5,5) / 2 = 2

Ответ: -3,5; 2