Solve for n.

n–19
3


3 or
5n+18
3
≤6
Write your answer as a compound inequality with integers.

1 answer

To solve the compound inequalities, we will break them down into two separate inequalities:

  1. \( \frac{n - 19}{3} \geq -3 \)
  2. \( \frac{5n + 18}{3} \leq 6 \)

Solving the first inequality:

  1. Start with: \[ \frac{n - 19}{3} \geq -3 \]

  2. Multiply both sides by 3 (since 3 is positive, the inequality direction stays the same): \[ n - 19 \geq -9 \]

  3. Add 19 to both sides: \[ n \geq 10 \]

Solving the second inequality:

  1. Start with: \[ \frac{5n + 18}{3} \leq 6 \]

  2. Multiply both sides by 3: \[ 5n + 18 \leq 18 \]

  3. Subtract 18 from both sides: \[ 5n \leq 0 \]

  4. Divide both sides by 5 (again, 5 is positive, so the inequality direction stays the same): \[ n \leq 0 \]

Final Expression:

Now, we combine the results of both inequalities to form a compound inequality:

\[ n \geq 10 \quad \text{or} \quad n \leq 0 \]

Thus, the solution is expressed as: \[ n \in (-\infty, 0] \cup [10, \infty) \]

In terms of integers, the solution can be written as:

\[ n \leq 0 \quad \text{or} \quad n \geq 10 \]

This describes the set of all integers that satisfy either of the conditions.