Answer:
Number of T-SHIRT sold = x = 110
Number of sweatshirt = y = 40
Explanation:
Let
Number of T-SHIRT sold = x
Number of sweatshirt = y
The number of T-shirts sold was 10 fewer than three times the number of sweatshirts sold.
x = 3y - 10
Cost of each T-SHIRT = $11
Cost of sweatshirt = $19
Total cost = $1,970
Total = x + y
1,970 = 11(3y - 10) + 19y
1970 = 33y - 110 + 19y
1970 + 110 = 33y + 19y
2080 = 52y
y = 2,080/52
y = 40
Substitute y = 40 into
x = 3y - 10
x = 3(40) - 10
x = 120 - 10
x = 110
Number of T-SHIRT sold = x = 110
Number of sweatshirt = y = 40