a)
`ĐKXĐ: xne+-3;xne-1`
`Q=(1-( x-11)/(x+1)):((3+x)/(x-3)-(36)/(9-x^2) - (x-3)/(x+3) )`
`=12/(x+1).((x+3)(x-3))/(12x+36)`
`=(x-3)/(x+1)`
b)
`Q=m`
`⇔(x-3)/(x+1)=m`
`⇔x-3=mx+m`
`⇔(m-1)m=-3x-m`
`⇒m-1ne0⇒mne1`
c)
`Q=-x`
`⇔(x-3)/(x+1)=-x`
`⇔x-3=-x(x+1)`
`⇔x^2+2x-3=0`
`⇔`\(\left[ \begin{array}{l}x=1(tm)\\x=-3(ktm)\end{array} \right.\)
d)
`Q<1`
`⇔(x-3)/(x+1)<1`
`⇔(x-3)/(x+1)-1<0`
`⇔(-4)/(x+1)<0`
`⇔x>(-1)`
$\Rightarrow x>-1, x\neq 3$