\( \Large ? = 6.39 \times 128.948 + 5.215 \div 12.189 + 25.056 \) \(= \Large 6.39 \times 128.948 + 5.215 \times \frac{1}{12.189} + 25.056 \)
\(= \Large 823.97772 + 0.427844778 + 25.056 \)
\(= \Large 849.4615648 = 850 \)