Answer:
14
Explanation:
A = length x width
l = length
w = 3l + 2
A = l(3l + 2) = 56
3l² + 2l - 56 = 0
Now you have a polynomial you can solve by factoring or using the quadratic equation to find the 2 roots of l:
using the quadratic equation with a = 3, b = 2, c = -56
l = 4, -14/3
Disregarding the negative root,
l = 4
Therefore, w = 3(4) + 2 = 14