a) A=( 1/x-2 - 2x/4-x2 +1/2+x ) * (2/x-1)
A= 2/[(x-2)(x-1) - 4x/[(4-x^2)(x-1) +2/[(2+x)(x-1)
A= -2/[(x-2)(x-1)] - 4x/[(x-2)(x+2)(x-1)] +2/[(x+2)(x-1)]
A=$\frac {-2(x+2)-4x+2(x-2)}{(x-2)(x+2)(x-1)}$
A=$\frac {-2x-4-4x+2x-4}{(x-2)(x+2)(x-1)}$
A=$\frac {-4x-8}{(x-2)(x+2)(x-1)}$
A=$\frac {-4(x+2)}{(x-2)(x+2)(x-1)}$
A=$\frac {-4}{(x-2)(x-1)}$
b)
A=$\frac {-4}{(x-2)(x-1)}$=$\frac {-4}{(4-2)(4-1)}$=$\frac {-4}{(2)*(3)}$=-2/3
A=$\frac {-4}{(x-2)(x-1)}$=$\frac {-4}{(2-2)(2-1)}$=$\frac {-4}{(0)*(1)}$ (!)
c)
A=$\frac {-4}{(x-2)(x-1)}$=1/2
⇔(x-2)(x-1)=-4: 1/2=-8
⇔x²-3x+2+8=0
⇔x²-3x+10=0
⇔(x+2)(x-5)=0
⇔\(\left[ \begin{array}{l}x=-2\\x=5\end{array} \right.\)
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