Answer:the number of short sleeves shirt sold is 15
the number of long sleeves shirt sold is 5
Explanation:
Let x represent the number of short sleeves shirt sold by the student council.
Let y represent the number of long sleeves shirt sold by the student council.
The student council sells short sleeves for $5 each and long sleeve for $6 each. They were sold for a total of $105. This means that
5x + 6y = 105 - - - - - - - - - -1
The total number of shirts sold is 20. This means that
x + y = 20
Substituting x = 20 - y into equation 1, it becomes
5(20 - y) + 6y = 105
100 - 5y + 6y = 105
- 5y + 6y = 105 - 100
y = 5
x = 20 - y = 20 - 5
x = 15