20-x^2/y-x

Solution for 20-x^2/y-x equation:

x in (-oo:+oo)

20-x-((x^2)/y) = 0

x^2*(-y^-1)-x+20 = 0

DELTA = (-1)^2-(4*20*(-y^-1))

DELTA = 1-80*y^-1

1-80*y^-1 = 0

-80*y^-1 = -1 // : -80

y^-1 = 1/80

-1 < 0

1/(y^1) = 1/80 // * y^1

1 = 1/80*y^1 // : 1/80

80 = y^1

y = 80

DELTA = 0  <=>  t_1 = 80

x = 1/(2*(-y^-1)) i y = 80

( x = ((1-80*y^-1)^(1/2)+1)/(2*(-y^-1)) or x = (1-(1-80*y^-1)^(1/2))/(2*(-y^-1)) ) i y > 80

y-80 > 0

y-80 > 0 // + 80

y > 80

x in { 1/(2*(-y^-1)), ((1-80*y^-1)^(1/2)+1)/(2*(-y^-1)), (1-(1-80*y^-1)^(1/2))/(2*(-y^-1)) }