Question 985641
n = number of 5-centavo coins
d = number of 10-centavo coins


5n + 10d = 305
n = d + 19


Substitute the second equation into the first.


5(d + 19) + 10d = 305
5d + 95 + 10d = 305
15d = 210
d = 14


There are 33 5-centavo coins and 14 10-centavo coins.