最佳答案:1/4x除以2/5=5/81/4x=5/8*2/51/4x=1/4x=1
最佳答案:7x/123456-4x/9765=0x*(7/123456-4/9765)=0x=0
最佳答案:={[(x+1)(x-1)-3]/(x-1)}÷[x(x²-4)/(x-1)²]=[(x²-4)/(x-1)]×[(x-1)²/x(x²-4)]=(x-1)/x