Since V is a point on the line UW, therefore:
the length of UV + the length of VW = the length of UW
19 + 4x - 20 = 6x - 35
19 - 20 + 35 = 6x - 4x
34 = 2x
x = 34/2 = 17
Based on this:
UW = 6x - 35 = 6(17) - 35 = 67 cm
UV = 19 cm
VW = 4x - 20 = 4(17) - 20 = 48 cm