To solve this problem, we need to evaluate the given expression and determine the value of x.
Let's break down the expression given:
$3 \cdot X \cdot 7 + 15 \div 3
We can simplify this expression using the order of operations (PEMDAS/BODMAS):
First, we perform the multiplication: 3 * X * 7 = 21X
Then, we perform the division: 15 ÷ 3 = 5
Finally, we add the results of the multiplication and division: 21X + 5
The expression is equal to 110, so we can set up the equation:
21X + 5 = 110
To isolate X, we subtract 5 from both sides of the equation:
21X + 5 - 5 = 110 - 5
21X = 105
To solve for X, we divide both sides of the equation by 21:
X = 105 / 21
X = 5
The value of X is 5.
The answer is: 5
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
Find $3 \cdot X \cdot 7 + 15 \div 3. 110. What is the value of unknown variable X?

### Answer:
