Explanation:
Hey, there!!
You can solve it simply,
1.
Given,
x= 1 , y=2 , z= 3
To solve:



Taking LCM,

Therefore, the final answer is 4/5.
2.
Given,
x= 1 , y= -2, z= -1.
To solve:


Taking LCM,


Cancelling the minus sign,

is the final answer.
3.
Given,
x= -3, y= -1, z= 4
To solve:




Therefore, the answer is 10/9.
4.
Given,
x= 1/2, y=1, z=1.
To solve:


Simplifying them ,


Therefore, the answer is 3.
Hope it helps...