Answer:
Step-by-step explanation:
We assume this is a geometry question in which point Y is between X and Z on the segment XZ. Then the appropriate relation is ...
XY +YZ = XZ
4x +3x = 42
7x = 42
x = 6
3x = 18 = YZ
x + 4y = 4
4y = 4 - x
multiply both sides by 1/4
y = 1/4( 4- x)
y = 1- 1/4x
