Đáp án: $\frac{125}{6}$
Giải thích các bước giải: $$\frac{351}{6}\times \frac{1}{\frac{4}{5}}+\frac{\frac{-451}{6}}{\frac{-4}{5}}\\=\frac{351\times 5}{6(-4)}+\frac{\frac{-451}{6}}{\frac{-4}{5}}\\=\frac{117\times 5}{2(-4)}+\frac{\frac{-451}{6}}{\frac{-4}{5}}\\=\frac{117\times 5}{2(-4)}+\frac{-\frac{451}{6}\times 5}{-4}\\=\frac{117\times 5}{2(-4)}+\frac{\frac{-451\times 5}{6}}{-4}\\=\frac{117\times 5}{2(-4)}+\frac{-451\times 5}{6(-4)}\\=\frac{117\times 5}{-8}-\frac{451\times 5}{-24}\\=\frac{585}{-8}+\frac{-2555}{-24}\\=\frac{-585}{8}-\frac{2555}{-24}\\=\frac{-585}{8}+\frac{2555}{24}\\=\frac{-1755}{24}+\frac{2555}{24}\\=\frac{-1755+2255}{24}\\=\frac{500}{24}\\=\frac{125}{6}$$
