PS:/为分数线1.若x/y=3/4,求(x+y)/y,x/(y-x),(x+y)/(y-x)2.已知x/2=y/3=z/4,求(x+y-2z)/2x-y3.已知k=2a/(b+c)=2b/(a+c)=2c/(a+b),求k的取值4.如图,点C`B在线段上,AD/DB=AC/CB,若AB=6cm,AC=3.6cm,求BD,AD图大概是这样的-----------------

PS:/为分数线1.若x/y=3/4,求(x+y)/y,x/(y-x),(x+y)/(y-x)2.已知x/2=y/3=z/4,求(x+y-2z)/2x-y3.已知k=2a/(b+c)=2b/(a+c)=2c/(a+b),求k的取值4.如图,点C`B在线段上,AD/DB=AC/CB,若AB=6cm,AC=3.6cm,求BD,AD图大概是这样的-----------------
PS:/为分数线
1.若x/y=3/4,求(x+y)/y,x/(y-x),(x+y)/(y-x)
2.已知x/2=y/3=z/4,求(x+y-2z)/2x-y
3.已知k=2a/(b+c)=2b/(a+c)=2c/(a+b),求k的取值
4.如图,点C`B在线段上,AD/DB=AC/CB,若AB=6cm,AC=3.6cm,求BD,AD
图大概是这样的
----------------------------------------------
A C B D
晕...
倒塌..图改不了.
A在最左端,C在1/5左右的位置.B大概在1/2,D在最右端

PS:/为分数线1.若x/y=3/4,求(x+y)/y,x/(y-x),(x+y)/(y-x)2.已知x/2=y/3=z/4,求(x+y-2z)/2x-y3.已知k=2a/(b+c)=2b/(a+c)=2c/(a+b),求k的取值4.如图,点C`B在线段上,AD/DB=AC/CB,若AB=6cm,AC=3.6cm,求BD,AD图大概是这样的-----------------
1.
设x=3a,y=4a
(x+y)/y=7a/4a=7/4
x/(y-x)=3a/a=3
(x+y)/(y-x)=7a/a=7
2.
设x/2=y/3=z/4=a
∴x=2a,y=3a,z=4a
(x+y-2z)/2x-y =-1
3.
2a/(b+c)=2b/(a+c)
∴a×a+ac=b×b+bc(式1)
2b/(a+c)=2c/(a+b)
∴b×b+ab=ac+c×c(式2)
(式1)+(式2):a×a-c×c=bc-ab
化简：a+c=-b
∴k=2b/(a+c)=-2
4.
AD/DB=(AB+BD)/BD=(6+BD)/BD=6/BD+1
AC/CB=3.6/(6-3.6)=3/2
∴6/BD+1=3/2
∴BD=12
AD=18