For this case we have to:
x: Let the variable representing the number of people to travel in the group
y: Let the variable representing the number of miles traveled.
If friends only have $22 then we have the following inequality:

Now, if there are three people in the group we have that 

The taxi can travel a maximum of 19.33 miles.
On the other hand, if the group wants to travel 10 miles then we have to y = 10.

Thus, they could travel a maximum of 5 people.
ANswer:

Traveling 3 people, the taxi can travel a maximum of 19.33 miles
Traveling 10 miles, a maximum of 5 people can travel
Answer:
y = 28x
Step-by-step explanation:
To find the answer, we need to divide the number of bushels by the number of acres. If the quotient is the same for all three divisions, then the quotient is how many times x is multiplied to get y.
140 / 5 = 28
224 / 8 = 28
420 / 15 = 28
Therefore, y = 28x is our answer.
In order to solve a negative exponent, you have to consider the multiplicative inverse of the base:

So, if we solve the negative exponent on the left hand side, we have

which is the right hand side.
15,409
fifteen thousand four hundred nine
5+(10,000) 4+(100)+9