Question 848827
x = number of 41 cent stamps
y = number of 7 cent stamps


x = 3y - 4
41x + 7y = 486


Substitute the first equation into the second.


41(3y - 4) + 7y = 486
123y - 164 + 7y = 486
130y = 650
y = 5


There are 5 7-cent stamps and 11 41-cent stamps.