# Question #beb6e

Sep 17, 2017

$\left[- 3 , 9\right)$

#### Explanation:

We have: $0 \le \frac{1}{3} x + 1 < 4$

Let's subtract $1$ from the inequality:

$R i g h t a r r o w 0 - 1 \le \frac{1}{3} x + 1 - 1 < 4 - 1$

$R i g h t a r r o w - 1 \le \frac{1}{3} x < 3$

Then, let's multiply by $3$:

$R i g h t a r r o w - 1 \times 3 \le \frac{1}{3} x \times 3 < 3 \times 3$

$\therefore - 3 \le x < 9$

Therefore, the solution interval to the inequality is $\left[- 3 , 9\right)$.