怎么算6/x+6/x+5=1,7x-x的平方=30,
问题描述:
怎么算6/x+6/x+5=1,7x-x的平方=30,
答
1: 6/x+6/(x+5)=1? 6/x+6/(x+5)=16(x+5)/[x(x+5)]+6x/[x(x+5)]=1 [6(x+5)+6x]/x(x+5)=1 (12x+30)/x(x+5)=1 x²-7x=0 ...