Respuesta :

Answer:

16 m.

Step-by-step explanation:

First, we can start by expressing the length and height each as an equation using the variables h, w, and l. Also, we can write the formula for volume, as V.

h = 5w

l = 8h

V = l × w × h

Now, we can use the equations for length and width to substitute into each other and the equation for volume to restrict the equation to only 2 variables (V and w).

h = 5w  -->  l = 8h  --> l = 8(5w)

V = 8(5w) × w × 5w = 200w³

Because we were given a value for volume, we can plug it into the equation.

(12.8 m³) = 200w³

Now, we can solve for w.

(12.8 m³) / 200 = (200w³) / 200

(0.064 m³) = w³

[tex]\sqrt[3]{(0.064m^{3} )}[/tex] = [tex]\sqrt[3]{w^{3} }[/tex]

(0.4 m) = w

Finally, now that we have the width, we can plug w into our original equation for length (l).

l = 8(5w)

l = 8(5(0.4 m)) = 16 m

So, our answer is the wall's length is 16 m!