2X+1-x-2分之1-(2X+1-X²-4分之4)等于多少?
问题描述:
2X+1-x-2分之1-(2X+1-X²-4分之4)等于多少?
答
2X+1-x-2分之1-(2X+1-X²-4分之4)=2x+1-1/(x-2)-(2x+1-4/(x²-4)=2x+1-1/(x-2)-2x-1+4/(x²-4)=4/(x²-4)-1/(x-2)=(4-x-2)/[(x-2)(x+2)]=-(x-2)/[(x-2)(x+2)]=-1/(x+2)