A systems problem. You have two things and you will get two answers but you only need the one. Number of coins.

X = nickles

Y = dimes

All values in pennies.

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X + Y = 39

5X + 10Y = 330

-----------------------------------------------------------------------Multiply first equation by - 5 and add to eliminate a variable.

- 5(X + Y = 39)

5X + 10Y = 330

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- 5X - 5Y = - 195

5X + 10Y = 330

============================add

5Y = 135

**Y = 27 coins ( = $2.70)**

**X = 12 coins ( = 60 cents)**

**======================The money = $3.30 so the check is valid. **

**Y = 27 coins**

**X = 12 coins**

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