#### Given 20 – 5 x < 5 (x + 8), find the smallest value of x, when

(i) x ∈ I

(ii) x ∈ W

(iii) x ∈ N.

**Solution:**

20 – 5 x < 5 (x + 8)

⇒ 20 – 5x < 5x + 40

⇒ – 5x – 5x < 40 – 20

⇒ – 10x < 20

⇒ – x < 2

⇒ x > – 2

(i) When x ∈ I, then smallest value = – 1.

(ii) When x ∈ W, then smallest value = 0.

(iii) When x ∈ N, then smallest value = 1. Ans.

#### Solve the following inequation and represent the solution set on the number line :

**Solution:**

We have

Hence, solution set is {x : -4 < x < 5, x ∈ R}

The solution set is represented on the number line as below.