Carson needs to mow 40 lines, and it takes him 2 minutes to mow one line. So the total time he spends mowing is 40 * 2 = 80 minutes.
He also needs to plant 8 rows of flowers, each with x flowers, and it takes him half a minute to plant each flower. So the total time he spends planting flowers is 8 * (1/2) * x = 4x minutes.
The total time Carson spends gardening is the sum of the time spent mowing and the time spent planting flowers: 80 + 4x minutes.
We are given that the total time is 108 minutes, so we can write: 80 + 4x = 108.
Solving for x, we get: 4x = 28.
Dividing both sides by 4, we get: x = 7.
The value of x is 7.
#### 7
The answer is: 7
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
Carson needs to mow the lawn and plant some flowers. Carson has to mow 40 lines to cover the whole yard, and it takes him 2 minutes to mow one line. He also needs to plant 8 rows of flowers, each with x flowers, and it takes him half a minute to plant each flower. How many minutes will Carson spend gardening?
If we know the answer to the above question is 108, what is the value of unknown variable x?

### Answer:
