I need help please help me out

Step-by-step explanation:
First one..
move the green dot one step to the left
Interactive table
U is under the operation a-b
where a = -1 and b = -2
U = -1 - (-2)
U = -1 + 2
U = 1
V is under the operation a-b
where a = -4 and b = 1
V = -4 -1
V = -5