To find the expression for the number of sodas left after \( t \) hours, we start by observing the pattern in how many sodas are left in the vending machine.
From the table:
- At hour 0, there are 310 sodas.
- At hour 1, there are 290 sodas, which means 20 sodas have been consumed in the first hour.
- At hour 2, there are 270 sodas, meaning another 20 sodas have been consumed in the second hour.
- At hour 3, there are 250 sodas, indicating that another 20 sodas have been consumed in the third hour.
We can see that the number of sodas decreases by 20 for each hour that passes. Thus, we can express the number of sodas left after \( t \) hours as:
\[ \text{Number of Sodas} = 310 - 20t \]
Therefore, the expression that gives the number of sodas left after \( t \) hours is:
\[ 310 - 20t \]