\(\dfrac{x^2+4x-12}{2-x}+\dfrac{x^3-125}{x-5}=15\)
\(\dfrac{x^2-2x+6x-12}{-\left(x-2\right)}+\dfrac{\left(x-5\right)\left(x^2+5x+25\right)}{x-5}=15\)
\(\dfrac{x\left(x-2\right)+6\left(x-2\right)}{-\left(x-2\right)}+x^2+5x+25=15\)
\(\dfrac{\left(x-2\right)\left(x+6\right)}{-\left(x-2\right)}+x^2+5x+25=15\)
\(-x-6+x^2+5x+25=15\)
\(x^2+4x+19=15\)
\(x^2+4x+19-15=0\)
\(x^2+4x+4=0\)
\(\left(x+2\right)^2=0\)
\(x+2=0\)
\(x=-2\)
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