Answer:
I dont know if I can answer if I don't have more information then the question
<span>Números racionales son números que pueden ser wriiten como una proporción, y pueden ser escritos como una fracción también. Un ejemplo de un número racional sería dos cuartos (2/4), medio (1/2), etc.</span>
99 km ... 9 liters
x km ... 12 liters
If the relationship is proportional, we have

from where
The answer is 132 kilometers.
For the lunch it would be 20$
Let n be a number of friends at the perty. If <span>dinner costs $30 per person, then it cost $30n for all friends.
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Robert has booked a banquet hall which costs <span>$200, then his total expenses are $200+30n.
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If the final bill is p, then p=<span>200+30n.
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Answer: p=<span>200+30n.</span>