To find out how far Alexa drove, you can use the formula:
\[ \text{Distance} = \frac{\text{Total Earnings}}{\text{Earnings per mile}} \]
In this case, Alexa's total earnings are $450.80 and her earnings per mile are $0.40. Plugging in the values:
\[ \text{Distance} = \frac{450.80}{0.40} \]
Now, perform the division:
\[ \text{Distance} = 1127 \]
So, Alexa drove 1127 miles.