Answer:
The weight of second fish
pound.
Step-by-step explanation:
Given You catch two fishes
Let weight of I fish = x pound
If the weight of II fish atleast 0.5 pound more than the weight of I fish
The weight of II fish=w pound
Therefore, 
Where x= Weight of I fish
w= Weight of II fish
= Less than or equal to
"+" = Sign of addition
Because the weight of II fish is greater than the weight of I fish
The required expression for the weight of II fish
pound.