1/5=X-9/X

Solution for 1/5=X-9/X equation:

D( X )

X = 0

X = 0

X = 0

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

1/5 = X-(9/X) // - X-(9/X)

9/X-X+1/5 = 0

9*X^-1-1*X^1+1/5*X^0 = 0

(1/5*X^1-1*X^2+9*X^0)/(X^1) = 0 // * X^2

X^1*(1/5*X^1-1*X^2+9*X^0) = 0

X^1

(1/5)*X-X^2+9 = 0

(1/5)*X-X^2+9 = 0

DELTA = (1/5)^2-(-1*4*9)

DELTA = 901/25

DELTA > 0

X = ((901/25)^(1/2)-(1/5))/(-1*2) or X = (-(1/5)-(901/25)^(1/2))/(-1*2)

X = ((901/25)^(1/2)-1/5)/(-2) or X = ((901/25)^(1/2)+1/5)/2

X in { ((901/25)^(1/2)-1/5)/(-2), ((901/25)^(1/2)+1/5)/2} 

X in { ((901/25)^(1/2)-1/5)/(-2), ((901/25)^(1/2)+1/5)/2 }