Writing Expressions

Kerry-Ann Grant

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Jun 18, 2020
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Renting a paddle boat costs $1200 for the first hour and $800 for every hour after that.
a) If h= the number of hours that a costumer wants to rent the boat, write the expression for the cost of the boat hire. _____
b) Test if your equation works by calculating the cost for renting a boat for one hour, 2 hours or for 6 hours.
1 hour ___. 2 hours____. 6 hours ___

How do I write these expressions, please?
Can anyone explain?
 

Jomo

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Sorry but we do not give solutions on this forum. We prefer to help you figure it out with helpful hints.

Boy that is one expensive boat rental place!

Imagine if you paid the renter after each hour. Note you pay $1200 just to be given a boat.

How much would it cost to rent the boat for 1 hour?
How much would it cost to rent the boat for 2 hours?
How much would it cost to rent the boat for 3 hours?
 

Kerry-Ann Grant

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Jun 18, 2020
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Thanks for your response.
So based on my understanding,
$1200 would cover for 1 hour,
2 hours = 1200+800
6 hours = 1200 + 5(800)

Just not sure how to write the answers for questions A & B as expressions.
 

Subhotosh Khan

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Thanks for your response.
So based on my understanding,
$1200 would cover for 1 hour,
2 hours = 1200+800
6 hours = 1200 + 5(800)

Just not sure how to write the answers for questions A & B as expressions.
Your calculations are correct - but you need to "observe" the pattern in your answers to be able to write expression. I'll start you off. You found:

for

1 hour ..\(\displaystyle \to \) 1200 ........................\(\displaystyle \to \) 1200 + ( 1 -1) * 800​
2 hours \(\displaystyle \to \) 1200+800 .............\(\displaystyle \to \) 1200 + ( 2 - 1) * 800​
6 hours \(\displaystyle \to \) 1200 + 5(800)......\(\displaystyle \to \) 1200 + ( 6 -1) * 800​

Do you see a pattern now.......

Can you write an expression for cost of renting for h (h≥1) hours?
 

HallsofIvy

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Jan 27, 2012
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Both of your calculations, for 2 and 6 hours, start with "1200" so your general formula should have !200 for the first hour plus the cost of the remaining time. Now, how did you get the "5" in the calculation for 6 hours? If you have the boat for "h" hours, how many hours are counted as "every hour after" the first?
 

Jomo

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Write down the 1st few terms, see what is exactly the same (it will be the exact same in the equation you find) and see what is changing. How does what change relate to the number of hours the boat is rented for. Is it also equal to the number of hours rental, is it always 7 more than the number of hours rented??
 
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