1/y-2+1/10=-4/5y-10

Solution for 1/y-2+1/10=-4/5y-10 equation:

D( y )

y = 0

y = 0

y = 0

y in (-oo:0) U (0:+oo)

1/y+1/10-2 = (-4/5)*y-10 // - (-4/5)*y-10

1/y-((-4/5)*y)+1/10-2+10 = 0

(4/5)*y+1/y+1/10-2+10 = 0

4/5*y^1+1*y^-1+81/10*y^0 = 0

(4/5*y^2+81/10*y^1+1*y^0)/(y^1) = 0 // * y^2

y^1*(4/5*y^2+81/10*y^1+1*y^0) = 0

y^1

(4/5)*y^2+(81/10)*y+1 = 0

(4/5)*y^2+(81/10)*y+1 = 0

DELTA = (81/10)^2-(1*4*(4/5))

DELTA = 6241/100

DELTA > 0

y = ((6241/100)^(1/2)-(81/10))/(2*(4/5)) or y = (-(81/10)-(6241/100)^(1/2))/(2*(4/5))

y = -1/8 or y = -10

y in { -10, -1/8} 

y in { -10, -1/8 }