Question 951803
length = w + 7
width = w
height = 3


3(w)(w + 7) = 294
w(w + 7) = 98
w^2 + 7w = 98
w^2 + 7w - 98 = 0
(w + 14)(w - 7) = 0


Distance has to be positive, so w = 7.


The box is 14 inches long, 7 inches wide, and 3 inches tall.