1/(x+1)+2/(x-2)=8/(x²-4)3x/(x+1)(x-2)=8/(x-2)(x+2)两边同乘以（x-2）3x/(x+1)=8/(x+2)3x(x+2)=8(x+1)3x²+6x=8x+83x²-2x-8=0(3x+4)(x-2)=0x= - 4/3或2∵x²-4为分母不等于0∴x²≠4∴x≠±...