Biết \(\dfrac{x}{3}=\dfrac{2}{3}+\dfrac{-1}{7}\) . Tìm x. \(\dfrac{11}{7}\) \(\dfrac{12}{7}\) \(\dfrac{10}{7}\) \(\dfrac{8}{7}\) Hướng dẫn giải: \(\dfrac{x}{3}=\dfrac{2}{3}+\dfrac{-1}{7}\) \(\Leftrightarrow\dfrac{x}{3}=\dfrac{11}{21}\) \(\Leftrightarrow x=\dfrac{3.11}{21}=\dfrac{11}{7}\)
Thực hiện phép tính \(\dfrac{-6}{7}+\dfrac{45}{64}+\dfrac{-1}{7}\) \(\dfrac{-19}{64}\) \(-\dfrac{9}{32}\) \(-\dfrac{5}{16}\) \(-\dfrac{21}{64}\)
Thực hiện phép tính \(\dfrac{5}{8}+\dfrac{-3}{4}+\dfrac{7}{12}+\dfrac{1}{24}\) . \(\dfrac{1}{2}\) \(\dfrac{3}{2}\) \(1\) \(\dfrac{3}{4}\) Hướng dẫn giải: \(\dfrac{5}{8}+\dfrac{-3}{4}+\dfrac{7}{12}+\dfrac{1}{24}\) \(=\dfrac{15}{24}+\dfrac{-18}{24}+\dfrac{14}{24}+\dfrac{1}{24}\) \(=\dfrac{15+\left(-18\right)+14+1}{24}\) \(=\dfrac{12}{24}=\dfrac{1}{2}\)
Thực hiện phép tính \(\dfrac{-2}{5}+\dfrac{3}{-4}+\dfrac{6}{7}+\dfrac{3}{4}+\dfrac{2}{5}\) \(\dfrac{6}{7}\) \(\dfrac{13}{7}\) \(\dfrac{1}{7}\) \(\dfrac{2}{7}\) Hướng dẫn giải: \(\dfrac{-2}{5}+\dfrac{3}{-4}+\dfrac{6}{7}+\dfrac{3}{4}+\dfrac{2}{5}\) \(=\left(-\dfrac{2}{5}+\dfrac{2}{5}\right)+\left(\dfrac{3}{-4}+\dfrac{3}{4}\right)+\dfrac{6}{7}\) \(=\dfrac{6}{7}\)
Thực hiện phép tính \(\dfrac{5}{11}+\dfrac{16}{22}+\dfrac{-12}{4}+\dfrac{-2}{11}\) . - \(2\) - \(3\) 2 \(4\) Hướng dẫn giải: \(\dfrac{5}{11}+\dfrac{16}{22}+\dfrac{-12}{4}+\dfrac{-2}{11}\) \(=\left(\dfrac{5}{11}+\dfrac{16}{22}+\dfrac{-2}{11}\right)+\dfrac{-12}{4}\) \(=\left(\dfrac{5}{11}+\dfrac{8}{11}+\dfrac{-2}{11}\right)+\left(-3\right)\) \(=1+\left(-3\right)=-2\)
Thực hiện phép tính \(\dfrac{7}{15}+\dfrac{-3}{4}+\dfrac{-20}{47}+\dfrac{8}{15}+\dfrac{-27}{47}\) \(\dfrac{-3}{4}\) \(-\dfrac{5}{4}\) \(-\dfrac{1}{4}\) \(-\dfrac{3}{2}\) Hướng dẫn giải: \(\dfrac{7}{15}+\dfrac{-3}{4}+\dfrac{-20}{47}+\dfrac{8}{15}+\dfrac{-27}{47}\) \(=\left(\dfrac{7}{15}+\dfrac{8}{15}\right)+\left(\dfrac{-20}{47}+\dfrac{-27}{47}\right)+\dfrac{-3}{4}\) \(=1+\left(-1\right)+\dfrac{-3}{4}=\dfrac{-3}{4}\)
Làm tính trừ: \(\dfrac{2}{3}-\left(-\dfrac{3}{4}\right)\) \(\dfrac{17}{12}\) \(-\dfrac{1}{12}\) \(\dfrac{1}{12}\) \(\dfrac{3}{2}\)
Thực hiện phép tính: \(\dfrac{-5}{8}-\dfrac{1}{2}\) \(-\dfrac{9}{8}\) \(-\dfrac{7}{8}\) \(-\dfrac{1}{8}\) \(\dfrac{5}{8}\)
Tìm x biết \(\dfrac{5}{6}+x=\dfrac{1}{4}\). \(-\dfrac{7}{12}\) \(-\dfrac{5}{12}\) \(-\dfrac{1}{12}\) \(-\dfrac{1}{3}\)
Thực hiện phép tính: \(\dfrac{4}{9}-\left(\dfrac{1}{2}+\dfrac{1}{4}\right)\) \(-\dfrac{11}{36}\) \(-\dfrac{1}{3}\) \(\dfrac{5}{18}\) \(-\dfrac{13}{36}\) Hướng dẫn giải: \(\dfrac{4}{9}-\left(\dfrac{1}{2}+\dfrac{1}{4}\right)\) \(=\dfrac{4}{9}-\left(\dfrac{2}{4}+\dfrac{1}{4}\right)\) \(=\dfrac{4}{9}-\dfrac{3}{4}\) \(=\dfrac{16}{36}-\dfrac{27}{36}\) \(=-\dfrac{11}{36}\)
