{(x-2)-12/x-2}/(4-x)/(x＋2)
=(x-14)/(x-2)*(x+2)/(4-x)
=(x-14)(x+2)/(x-2)(4-x),x＝－4＋√3
=(√3-18)(√3-2)/(√3-6)(8-√3)
=(39-20√3)/(14√3-51)