第一题,（1-x)/(x-2)-1/(2-x)=-2（1-x)/(x-2)+1/(x-2)=-2（2-x)/(x-2）=-2无解第二题2x/(x+3)+1=7/(2x+6)(3x+3)/(x+3)=7/2(x+3)2(3x+3)=7x=1/6第三题(x+1)(x+1)/(x*x-1)-4/(x*x-1)=1(x*x+2x-3)/(x*x-1)=12x-3=-1x=1...