Explain how to figure out the weight of a piece labeled with a letter by reasoning about the diagram (first answer gets brainliest) (please help ASAP)

Answer:
1:2.2+Z=6.8
2:you have to minus 2.2 and 6.8 to get 4.6 to even the weight
3: minus 2.2 n 6.8 =4.6
Step-by-step explanation: