Question 1001664
d = number of dimes
q = number of quarters


d + q = 29
10d + 25q = 455


Multiply the first equation by 25. We are going to eliminate the variable q.


25d + 25q = 725
10d + 25q = 455


Subtract to get 15d = 270, so d = 18.


Lindsay has 18 dimes and 11 quarters.