X-{X/5+5+X/4+7+1/2[X-(X/5+5+X/4+7)]}=X/8 要过程

显示全部楼层 · 2013-6-1 09:24:02

解:原式：X－X/5－5－X/4－7－1/2(x－X/5-5-x/4-7)=x/8
1x（x-x/5-5-x/4-7）-1/2(x-x/5-5-x/4-7)=x/8
(1-1/2)(x-x/5-5-x/4-7))=x/8
1/2(11x/20-12)=x/8
11x/40-6=5x/40
-6=5x/40-11x/40
3/20x=6
x=40不知对不对。。。...

千问 · 2013-6-1 09:24:02

X-{X/5+5+X/4+7+1/2[X-(X/5+5+X/4+7)]}=X/8X-{9X/20+12+1/2[X-(9X/20+12)]}=X/8X-{9X/20+12+1/2[11X/20-12)]}=X/8X-{9X/20+12+11X/40-6}=X/8X-{29X/40+6}=X/811X/40-6=X/83X/20=6...