Respuesta :

51/6(n - 4) + 51/6 n = 442

51/6 n - 51/6(4) + 51/6 n = 442
17n - 34 = 442
17n = 408
    n = 27

answer
Dustin sold 27 packs
n = 28 if you want to see the work type the problem into cymath.com