(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Bob has 50 coins, all nickels and dimes, worth a total of 4.85. How many nickels does he possess?

2. Relevant equations

n + d = 50

5n + 10d = 485

Multiplying the first equation by 10, we obtain 10n+10d=500

Subtracting the second equation from the third equation, we get 5n=15, so n = 3

3. The attempt at a solution

I have the solution. My question is:

Why do you multiply the first equation by 10 to begin with? Also, why do you then subtract one equation from the other? What is the rationale to it?

Thanks in advance

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# Homework Help: Nickels and Dimes = some amount, how many nickels?

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