How to find the answer

Answer:
y=7-2*-1
y=7+2
y=8
y=7-2*3
y=7-6
y=1
y=7-2*5
y=7-10
y=-3
Step-by-step explanation:
place 8 in first box,1 in second and -3 in third
Answer:
9,1,-3
Step-by-step explanation:
y =7-2x
When x=-1,
y= 7-(2×-1)
y= 7-(-2)
y= 7+2
y=9
When x=3,
y=7-2(3)
y=7-6
y=1
When x=5,
y=7-2(5)
y=7-10
y=-3