[100/(x+3)]+[240/(x-1)]=340/x [10/(x+3)]+[24/(x-1)]=34/x [5/(x+3)]+[12/(x-1)]=17/x (化简,左右同除20)(5x-5+12x+36)/[(x+3)(x-1)]=17/x(通分)(17x+31)/(x^2+2x-3)=17/x17x^2+34x-51=17x^2+31x(交叉相乘)34x-31x...