Given,
−2≤21−32x≤165⇒−2≤21−32x≤611⇒−2−21≤21−32x−21≤611−21By subtracting 21 on both sides of inequality in the above line.⇒−25≤−32x≤68⇒−25×6≤−32x×6≤68×6 (Multiplying complete equation with 6) ⇒−15≤−4x≤8⇒15≥4x≥−8⇒415≥x≥−2
Since x ∈ N,
∴ Solution Set = {1, 2, 3}
The graph of the solution set is shown by thick dots on the number line.