Solve the rational inequality.

[tex]\[ \frac{30}{x+6} \leq 5 \][/tex]

What is the solution set?

[tex]\[ \boxed{} \][/tex]

(Type your answer in interval notation. Use integers or fractions for any numbers in the expression.)



Answer :

To solve the inequality [tex]\(\frac{30}{x + 6} \leq 5\)[/tex], we will follow a step-by-step method:

1. First, isolate the fraction:
[tex]\[ \frac{30}{x + 6} \leq 5 \][/tex]

2. Eliminate the fraction by multiplying both sides by [tex]\(x + 6\)[/tex]:
We need to consider two cases, because the sign of [tex]\(x + 6\)[/tex] affects the inequality:
- When [tex]\(x + 6 > 0\)[/tex] (i.e., [tex]\(x > -6\)[/tex])
- When [tex]\(x + 6 < 0\)[/tex] (i.e., [tex]\(x < -6\)[/tex])

### Case 1: [tex]\(x + 6 > 0\)[/tex] (i.e., [tex]\(x > -6\)[/tex])
In this case, multiplying both sides by [tex]\(x + 6\)[/tex] (a positive number) does not change the direction of the inequality:
[tex]\[ 30 \leq 5(x + 6) \][/tex]
[tex]\[ 30 \leq 5x + 30 \][/tex]

Subtract 30 from both sides:
[tex]\[ 0 \leq 5x \][/tex]
[tex]\[ 0 \leq x \][/tex]
or equivalently:
[tex]\[ x \geq 0 \][/tex]

Since we are considering the case [tex]\(x + 6 > 0\)[/tex], we have [tex]\(x \geq 0\)[/tex].

### Case 2: [tex]\(x + 6 < 0\)[/tex] (i.e., [tex]\(x < -6\)[/tex])
In this case, multiplying both sides by [tex]\(x + 6\)[/tex] (a negative number) reverses the direction of the inequality:
[tex]\[ 30 \geq 5(x + 6) \][/tex]
[tex]\[ 30 \geq 5x + 30 \][/tex]

Subtract 30 from both sides:
[tex]\[ 0 \geq 5x \][/tex]
[tex]\[ 0 \geq x \][/tex]
or equivalently:
[tex]\[ x \leq 0 \][/tex]

However, in this scenario we have [tex]\(x < -6\)[/tex], which is already included in the region we need to consider.

### Combine the two cases:
- From Case 1, we have [tex]\(x \geq 0\)[/tex].
- From Case 2, we have [tex]\(x < -6\)[/tex].

Since these results represent mutually exclusive conditions, we express this in interval notation:

### Solution set:
[tex]\[ x < -6 \text{ or } x \geq 0 \][/tex]

In interval notation, this is written as:
[tex]\[ (-\infty, -6) \cup [0, \infty) \][/tex]

This is the final solution set for the inequality [tex]\(\frac{30}{x + 6} \leq 5\)[/tex].