I don't know what type of math you categorize this questions but here it is. Please help.

Yaatski

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Apr 6, 2021
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How much money would I start with if, in spending 1/5 and the 1/5 of the remaining amount, I had altogether spent 72 dollars?
Please show me how to solve this. I am currently preparing for an entrance exam and I would love if someone could help me with a few other questions over on discord. Thanks in advance.
 

Subhotosh Khan

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How much money would I start with if, in spending 1/5 and the 1/5 of the remaining amount, I had altogether spent 72 dollars?
Please show me how to solve this. I am currently preparing for an entrance exam and I would love if someone could help me with a few other questions over on discord. Thanks in advance.
Assume yo ur starting amount = x

Then:

x/5 + 1/5 * 4 * x/5 = 72

Solve for 'x'.
 

JeffM

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Sep 14, 2012
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More intuitive for me is to start with

\(\displaystyle \dfrac{1}{5} * x + \dfrac{1}{5} * \left ( x - \dfrac{1}{5} * x \right )= 72 \implies \dfrac{x}{5} + \dfrac{1}{5} * \left ( \dfrac{5x}{5} - \dfrac{x}{5} \right ) = 72 \implies \dfrac{x}{5} + \dfrac{1}{5} * \dfrac{4x}{5} = 72.\)

Notice that I get to the same place as Subhotosh Khan. His way uses fewer steps, but my way starts closer to the original words. in either case, you must solve for x.

It is beginning algebra.
 
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