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D( x )
x = 0
x = 0
x = 0
x in (-oo:0) U (0:+oo)
(4*x-(16/x)-5)*(3*x-((15/8)*x)-32) = 0
(4*x-16*x^-1-5)*(3*x+(-15/8)*x-32) = 0
(4*x-16*x^-1-5)*(9/8*x-32) = 0
4*x-16*x^-1-5 = 0
4*x^1-16*x^-1-5*x^0 = 0
(4*x^2-5*x^1-16*x^0)/(x^1) = 0 // * x^2
x^1*(4*x^2-5*x^1-16*x^0) = 0
x^1
4*x^2-5*x-16 = 0
4*x^2-5*x-16 = 0
DELTA = (-5)^2-(-16*4*4)
DELTA = 281
DELTA > 0
x = (281^(1/2)+5)/(2*4) or x = (5-281^(1/2))/(2*4)
x = (281^(1/2)+5)/8 or x = (5-281^(1/2))/8
x in { (5-281^(1/2))/8, (281^(1/2)+5)/8}
(x-((5-281^(1/2))/8))*(x-((281^(1/2)+5)/8)) = 0
(x-((5-281^(1/2))/8))*(x-((281^(1/2)+5)/8))*(9/8*x-32) = 0
( 9/8*x-32 )
9/8*x-32 = 0 // + 32
9/8*x = 32 // : 9/8
x = 32/9/8
x = 256/9
( x-((281^(1/2)+5)/8) )
x-((281^(1/2)+5)/8) = 0 // + (281^(1/2)+5)/8
x = (281^(1/2)+5)/8
( x-((5-281^(1/2))/8) )
x-((5-281^(1/2))/8) = 0 // + (5-281^(1/2))/8
x = (5-281^(1/2))/8
x in { 256/9, (281^(1/2)+5)/8, (5-281^(1/2))/8 }
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