Solve 'm trying but unable to solve

0 or ±a √(27/28)

Step-by-step explanation:

∛(x+a) + ∛(x−a) = ∛x

Cube both sides:

(x+a) + 3 ∛(x+a)² ∛(x-a) + 3 ∛(x+a) ∛(x−a)² + (x−a) = x

3 ∛(x+a)² ∛(x-a) + 3 ∛(x+a) ∛(x−a)² + 2x = x

3 ∛(x+a)² ∛(x-a) + 3 ∛(x+a) ∛(x−a)² + x = 0

Factor from the first two terms:

3 ∛(x+a) ∛(x-a) (∛(x+a) + ∛(x−a)) + x = 0

Substituting from the first equation:

3 ∛(x+a) ∛(x-a) ∛x + x = 0

Factor:

∛x (3 ∛(x+a) ∛(x-a) + ∛x²) = 0

x = 0

or

3 ∛(x+a) ∛(x−a) + ∛x² = 0

∛(x+a) ∛(x−a) = -1/3 ∛x²

Cube both sides:

(x+a)(x−a) = -1/27 x²

x² − a² = -1/27 x²

28/27 x² = a²

x = ±a √(27/28)

it is a. 4.2 because 7.6-3.4 gets the remaining length of 4.2. i might be wrong but i am pretty sure this is the answer.