(x-3)(72/x+4)=72

Solution for (x-3)(72/x+4)=72 equation:

D( x )

x = 0

x = 0

x = 0

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

(x-3)*(72/x+4) = 72 // - 72

(x-3)*(72/x+4)-72 = 0

(x-3)*(72*x^-1+4)-72 = 0

(x-3)*(72*x^-1+4)-72 = 0

4*x-216*x^-1-12 = 0

4*x-216*x^-1-12 = 0

4*(x-54*x^-1-3) = 0

1*x^1-54*x^-1-3*x^0 = 0

(1*x^2-3*x^1-54*x^0)/(x^1) = 0 // * x^2

x^1*(1*x^2-3*x^1-54*x^0) = 0

x^1

x^2-3*x-54 = 0

x^2-3*x-54 = 0

DELTA = (-3)^2-(-54*1*4)

DELTA = 225

DELTA > 0

x = (225^(1/2)+3)/(1*2) or x = (3-225^(1/2))/(1*2)

x = 9 or x = -6

x in { -6, 9} 

4*(x+6)*(x-9) = 0

4*(x+6)*(x-9) = 0

( x+6 )

x+6 = 0 // - 6

x = -6

( x-9 )

x-9 = 0 // + 9

x = 9

x in { -6, 9 }