Answer:
The dimensions are thus 4 by 10 units
Step-by-step explanation:
Rewrite w(w + 6) = 40 in standard quadratic form ax^2 + bx + c = 0:
w^2 + 6w - 40 = 0
This factors as follows:
w^2 + 6w - 40 = 0 => (w + 10)(w - 4) = 0.
Solving for w, we get w = 4 (and also the unhelpful w = -10).
The width of the rectangle is 4 and the length is 4 + 6, or 10.
The dimensions are thus 4 by 10 units, with area = 40 units^2
