Solve: `5x-15ge0`.

Answer

To solve the inequality \( 5x - 15 \geq 0 \), we will follow these steps:

### Step 1: Rewrite the inequality
We start with the given inequality:
\[ 5x - 15 \geq 0 \]

### Step 2: Add 15 to both sides
To isolate the term with \( x \), we add 15 to both sides of the inequality:
\[ 5x - 15 + 15 \geq 0 + 15 \]
This simplifies to:
\[ 5x \geq 15 \]

### Step 3: Divide both sides by 5
Next, we divide both sides of the inequality by 5. Since 5 is a positive number, the direction of the inequality remains the same:
\[ \frac{5x}{5} \geq \frac{15}{5} \]
This simplifies to:
\[ x \geq 3 \]

### Step 4: Write the solution in interval notation
The solution \( x \geq 3 \) means that \( x \) can take any value greater than or equal to 3. In interval notation, this is expressed as:
\[ x \in [3, \infty) \]

### Final Answer
Thus, the solution to the inequality \( 5x - 15 \geq 0 \) is:
\[ x \in [3, \infty) \]

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