Tính giá trị biểu thức \(0,5.\dfrac{4}{17}.3\dfrac{5}{21}.\Big(-\dfrac{7}{23}\Big)\).
\(\dfrac{-8}{69}.\)\(\dfrac{-7}{69}.\)\(\dfrac{-5}{38}.\)\(\dfrac{7}{2}.\)Hướng dẫn giải:\(0,5.\dfrac{4}{17}.3\dfrac{5}{21}.\Big(-\dfrac{7}{23}\Big)\)
\(=\dfrac{1}{2}.\dfrac{4}{17}.\dfrac{68}{21}.\dfrac{-7}{23}\)
\(=\dfrac{2}{17}.\dfrac{68}{21}.\dfrac{-7}{23}\)
\(=\dfrac{8}{21}.\dfrac{-7}{23}\)
\(=\dfrac{-8}{69}.\)
