初二几道简单的分式数学题

显示全部楼层 · 2013-8-21 19:54:53

1/a-1/b=b/ab-a/ab=(b-a)/ab(x^2+4x+4)/(x^2-4)-x/(x-2)=(x+2)^2/(x+2)(x-2)-x/(x-2)=(x+2)/(x-2)-x/(x-2)=2/(x-2)1/b+2/b=(1+2)/b=3/b...

千问 · 2013-8-21 19:54:53

（1）1/a-1/b=b/ab-a/ab=(b-a)/ab(2)(x^2+4x+4)/(x^2-4)-x/(x-2)=(x+2)^2/[(x+2)(x-2)]-x/(x-2)=(x+2)/(x-2)-x/(x-2)=(x+2-x)/(x-2)=2/(x-2)(3)1/b+2/b=(1+2)/b=3/b...

千问 · 2013-8-21 19:54:53

1/a-1/b=b/ab-a/ab=(b-a)/ab(x^2+4x+4)/(x^2-4)-x/(x-2)=(x+2)^2/(x+2)(x-2)-x/(x-2)=2/(x-2)3/b...