8.(10分)Give an asymptotic upper bound for \( \mathrm{T(n)} = 7\mathrm{T}\left(\lfloor \mathrm{n} / 3\rfloor \right) + \mathrm{n}^2 \) where \( \mathrm{T(n)} \) is constant for \( \mathfrak{n} < 3 \). Your upper bound should be as tight as possible.