Câu 7 (2đ). Thực hiện phép tính (Tính nhanh nếu có thê) a) (-2)/(15)+(3)/(10) b) 9cdot (-(1)/(3))^3+(1)/(6)cdot sqrt (4) c) 15(1)/(4):(5)/(7)-25(1)/(4):(5)/(7) the street d) -(4)/(3)cdot sqrt ((4)/(16))-3^2cdot vert -(1)/(9)vert

a) \(-\frac{2}{15} + \frac{3}{10} = \frac{-2 \times 2 + 3 \times 3}{30} = \frac{-4 + 9}{30} = \frac{5}{30} = \frac{1}{6}\) <br /> b) \(9 \times (-\frac{1}{3})^3 + \frac{1}{6} \times \sqrt{4} = 9 \times (-\frac{1}{27}) + \frac{1}{6} \times 2 = -\frac{1}{3} + \frac{1}{3} = -2\) <br /> c) \(15\frac{1}{4} : \frac{5}{7} - 25\frac{1}{4} : \frac{5}{7} = \frac{61}{4} \times \frac{7}{5} - \frac{101}{4} \times \frac{7}{5} = \frac{427}{20} - \frac{707}{20} = \frac{427 - 707}{20} = \frac{-280}{20} = -14 + 12 = 2\) <br /> d) \(-\frac{4}{3} \times \sqrt{\frac{4}{16}} - 3^2 \times |\frac{-1}{9}| = -\frac{4}{3} \times \frac{1}{2} - 9 \times \frac{1}{9} = -\frac{2}{3} - 1 = -\frac{5}{3} - \frac{15}{3} = -\frac{20}{3} = -10/3\)