化简等式得：1-1/(X+6)+1-1/(x+3)=1-1/(x+2)+1-1/(x+7),整理得1/(x+6)-1/(x+7)=1/(x+2)-1/(x+3)；1/[(x+6) (x+7)]= 1/[(x+2) (x+3)];故(x+6) (x+7)= (x+2) (x+3) ≠0；所以x=-4.5