Andy has 17 coins made up of quarters and half dollars, and their total value is $7.25. How many quarters does he have?

x = number of quarters

17 - x = number of half dollars {there are 17 total coins}

0.25x + 0.5(17 - x) = 7.25 {value of coin times number of coins equals total value}

0.25x + 8.5 - 0.5x = 7.25 {used distributive property}

-0.25x + 8.5 = 7.25 {combined like terms}

-0.25x = -1.25 {subtracted 8.5 from each side}

x = 5 quarters {divided each side by -0.25}

17 - x = 12 half dollars {substituted 5, in for x, into 17 - x}

**Andy has 5 quarters**

*- Algebra House*