Some dimes and quarters

Bruce has $5.50 in dimes and quarters. He has 8 more quarters then dimes.
How many coins does he have?

x = number of dimes
x + 8 = number of quarters   {he has 8 more quarters than dimes} 

10x + 25(x + 8) = 550   {value of coin times number of coins equals total value}
10x + 25x + 200 = 550   {used distributive property}
35x + 200 = 550   {combined like terms}
35x = 350   {subtracted 200 from each side}
x = 10   {divided each side by 35}
x + 8 = 18   {substituted 8, in for x, into x + 8} 

10 dimes and 18 quarters


- Algebra House