To solve this problem, we need to determine the value of x, which represents the number of piles with 9 hands of bananas.
Let's break down the information given:
Number of monkeys: 12
Number of piles of bananas: 10
Number of hands in piles with 9 hands: x
Number of bananas per hand in piles with 9 hands: 14
Number of hands in remaining piles: 12 - x
Number of bananas per hand in remaining piles: 9
Number of bananas each monkey gets: 99
We can set up the equation as follows:
(Number of piles with 9 hands * Number of hands per pile * Number of bananas per hand) + (Number of remaining piles * Number of hands per pile * Number of bananas per hand) = Total number of bananas
(x * 9 * 14) + ((10 - x) * 12 * 9) = 12 * 99
Let's simplify and solve for x:
126x + (120 - 12x) * 9 = 1188
126x + 1080 - 108x = 1188
To isolate x, we subtract 1080 from both sides of the equation:
126x - 108x = 1188 - 1080
18x = 108
To solve for x, we divide both sides of the equation by 18:
x = 108 / 18
x = 6
The value of x is 6.
#### 6
The answer is: 6
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
A family of 12 monkeys collected 10 piles of bananas. x piles had 9 hands, with each hand having 14 bananas, while the remaining piles had 12 hands, with each hand having 9 bananas. Each monkey would get 99 bananas if they divide the bananas equally amongst themselves. What is the value of unknown variable x?

### Answer:
