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1,(x+ 2-x-2分之5)除以(x-2分之x-3) 2,x分之3-x-1分之4=x-x的平方分之6
3,化简求值 (1+1-2x+x的平方分之x的平方-1)(x-1)其中x=-2分之3
人气:109 ℃ 时间:2020-07-03 16:13:28
解答
[x+2-5/(x-2)]/[(x-3)/(x-2)]
=[(x^2-4-5)/(x-2)]/[(x-3)/(x-2)]
=(x^2-9)/(x-2)*(x-2)/(x-3)
=(x^2-9)/(x-3)
=(x-3)(x+3)/(x-3)
=x+3
3/x-4/(x-1)=6/(x-x^2)
3/x+4/(1-x)=6/(x-x^2)
3(1-x)+4x=6
3-3x+4x=6
3+x=6
x=3
经检验x=3是方程的解
[1+(x^2-1)/(1-2x+x^2)](x-1)
=[1+(x-1)(x+1)/(x-1)^2](x-1)
=[1+(x+1)/(x-1)](x-1)
=(x-1)+(x+1)/(x-1)*(x-1)
=x-1+x+1
=2x
=2*(-3/2)
=-3
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