Stephanie adds pennies, nickels, and quarters to a scale until the mass of the combined coins is 75 grams. Each penny has a mass of 2.5 grams, each nickel has a mass of 5 grams, and each quarter has a mass of 5.7 grams.

Create an equation to model this situation, where x is the number of pennies, y is the number of nickels, and z is the number of quarters that Stephanie can put on the scale so that the mass of the combined coins is exactly 75 grams.

Create an equation to model this situation, where x is the number of pennies, y is the number of nickels, and z is the number of quarters that Stephanie can put on the scale so that the mass of the combined coins is exactly 75 grams.

**x = number of pennies**

y = number of nickels

z = number of quarters

y = number of nickels

z = number of quarters

**2.5x + 5y + 5.7z = 75**{mass of each coin times number of coins equals total mass}

*Ask Algebra House*