Let x,y∈{−1,−2,−3,...}.
Since x≤−1, ∣x−1∣=1−x≥2.
Let A=∣x−1∣∈{2,3,4,5,...} and B=∣y+3∣∈{0,1,2,...}.
We require 2≤A×B≤5.
- If A=2 (x=−1): B∈{1,2}⟹∣y+3∣=1 or 2⟹y∈{−4,−2,−5,−1} (4 values).
- If A=3 (x=−2): B=1⟹∣y+3∣=1⟹y∈{−4,−2} (2 values).
- If A=4 (x=−3): B=1⟹y∈{−4,−2} (2 values).
- If A=5 (x=−4): B=1⟹y∈{−4,−2} (2 values).
Total combinations = 4+2+2+2=10.