Question:
Solve: 4x − 2 < 8, when
(i) x ∈ R
(ii) x ∈ Z
(iii) x ∈ N
Solution:
We have, $4 x-2<8$
$\Rightarrow 4 x<8+2$ (Transposing $-2$ to the RHS)
$\Rightarrow 4 x<10$
$\Rightarrow x<\frac{10}{4}$ (Dividing both the sides by 4 )
$\Rightarrow x<\frac{5}{2}$
(i) $x \in R$
Then, the solution of the given inequation is $\left(-\infty, \frac{5}{2}\right)$.
(ii) $x \in Z$
Then, the solution of the given inequation is $\{\ldots \ldots \ldots-3,-2,-1,0,1,2\}$.
(iii) $x \in N$
Then, the solution of the given inequation is $\{1,2\}$.