Answer:
shamir bought = 5 shirts
aldo bought = 6 shirts
Explanation:
let x be the shirts bought by shamir
then aldo bought, 2x - 4
x + 2x - 4 = 11
3x - 4 = 11
3x = 11 + 4
3x = 15
x = 15/3 = 5
thus,
shamir bought = x = 5 shirts
aldo bought = 2x - 4 = 2(5) - 4 = 10 - 4 = 6 shirts