Ok, so they are all balanced, so each side of the scale thing is equal to the other side.
A. 3 + x = 8
If we subtract 3 from 8, what’s left is 5 for x
x = 5
B. 2y = 12
Both y weights are equal, so dividing 12 by 2 says each y weight is 6.
y = 6
C. 4z = 11
All z weights are equal, so divide 11 by 4 to find the weight of z
z = 2.75
D. 3 4/5 + w = 13 4/5
Subtract 3 4/5 from 13 4/5 to find the weight of w
w = 10
Let me know if you have questions about this.