Answer:
8
Step-by-step explanation:
The bottom angles are equal, so the sides are equal
2x = 5x-12
Subtract 5x from each side
2x-5x= 5x-12-5x
-3x = -12
Divide by -3
x = 4
YZ = 5x-12 = 5(4) -12 = 20-12 =8