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有三人做工,甲独做天数是乙丙共做天数的A倍,乙独做天数是甲丙共做天数的B倍,丙独做天数是乙甲共做天数的C倍,求:C+1/1+B+1/1+C+1/1=?1/(a+1)+1/(b+1)+1/(c+1)=?上次问错了,
题目详情
有三人做工,甲独做天数是乙丙共做天数的A倍,乙独做天数是甲丙共做天数的B倍,丙独做天数是乙甲共做天数的C倍,求:
C+1/1 + B+1/1 + C+1/1=?
1/(a+1)+1/(b+1)+1/(c+1)=?
上次问错了,
C+1/1 + B+1/1 + C+1/1=?
1/(a+1)+1/(b+1)+1/(c+1)=?
上次问错了,
▼优质解答
答案和解析
C+1/1 + B+1/1 + C+1/1=2c+b+3
在怎么详细?合并就完了.
如果是1/(a+1)+1/(b+1)+1/(c+1)=?还有点意义,你问的没意义!
设:甲独做天数是x,乙独做天数是y,丙独做天数是z.
a=x/(y+z),b=y/(x+z),c=z/(x+y)
a+1=x/(y+z)+1=x/(y+z)+(y+z)/(y+z)=(x+y+z)/(y+z)
1/(a+1)=1/((x+y+z)/(y+z))=(y+z)/(x+y+z)
同理:1/(b+1)=(x+z)/(x+y+z)
1/(c+1)=(x+y)/(x+y+z)
1/(a+1)+1/(b+1)+1/(c+1)
=(y+z)/(x+y+z)+(x+z)/(x+y+z)+(x+y)/(x+y+z)
=(y+z+x+z+y+z)/(x+y+z)=2(x+y+z)/(x+y+z)=2
在怎么详细?合并就完了.
如果是1/(a+1)+1/(b+1)+1/(c+1)=?还有点意义,你问的没意义!
设:甲独做天数是x,乙独做天数是y,丙独做天数是z.
a=x/(y+z),b=y/(x+z),c=z/(x+y)
a+1=x/(y+z)+1=x/(y+z)+(y+z)/(y+z)=(x+y+z)/(y+z)
1/(a+1)=1/((x+y+z)/(y+z))=(y+z)/(x+y+z)
同理:1/(b+1)=(x+z)/(x+y+z)
1/(c+1)=(x+y)/(x+y+z)
1/(a+1)+1/(b+1)+1/(c+1)
=(y+z)/(x+y+z)+(x+z)/(x+y+z)+(x+y)/(x+y+z)
=(y+z+x+z+y+z)/(x+y+z)=2(x+y+z)/(x+y+z)=2
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