Dave has 41 coins. Some are $10 coins, and the rest are $20 coins. The value of coins adds up to $540. How many of each coin are there ?

Answer 1

Greetings! Lets solve this shall we ?

So, we must solve this system of linear equations by setting it up such that

x + y = 41

10.00x + 20.00y = 540.............We multiply the first equation by -10 such that

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-10.00x - 10.00y = -410

10.00x + 20.00y = 540

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10.00y = 130..............Then divide 10 to get

y = 13 - 20 dollar coins

Then plug 13 into the equation such that

x + 13 = 41...............Then subtract 13 to get

x = 28 - 10 dollar coins

I hope this helped!