已知点C分线段AB为AC:CB=5:7,点D分线段AB为AD:DB=5:11,CD长为10cm,求AB的长.

已知点C分线段AB为AC:CB=5:7,点D分线段AB为AD:DB=5:11,CD长为10cm,求AB的长.
已知点C分线段AB为AC:CB=5:7,点D分线段AB为AD:DB=5:11,CD长为10cm,求AB的长.

已知点C分线段AB为AC:CB=5:7,点D分线段AB为AD:DB=5:11,CD长为10cm,求AB的长.
A_____________D____C__________________________B
设AB=X
则AC=5/12X,AD=5/16X
∵CD=AC-AD
∴5/12X-5/16X=10
解得x=96
即AB=96cm