To find the total amount Leo should give, simply find the 20% of his bill then add it.
Total cost = $45.90 + ($45.90 × 0.20)
Total cost = $45.90 + $9.18
Total cost = $55.08
Therefore, Leo should give $55.08 in total to leave a 20% tip.
The answer to the solution of the equation 5x+2y=-1 is 1,-3)
Answer:

And we can use the cumulative distribution function given by:

And for this case we can write the probability like this:

And then the final answer for this case would be 
Step-by-step explanation:
For this case we define our random variable X "price of gasoline for a city in the USA" and we know the distribution is given by:

And for this case the density function is given by:

And we want to calculate the following probability:

And we can use the cumulative distribution function given by:

And for this case we can write the probability like this:

And then the final answer for this case would be 