Tính nhanh: a) 305 ´ 328 + 305 ´ 671 + 305
Giải thích
a) 305 ´ 328 + 305 ´ 671 + 305 | b) \(\frac{{11}}{4} \times \frac{8}{{14}} \times \frac{7}{{11}} \times \frac{5}{3}\) |
= 305 ´ (238 + 671 + 1) = 305 ´ 1000 = 305 000 | = \(\frac{{11}}{4} \times \frac{4}{7} \times \frac{7}{{11}} \times \frac{5}{3} = \left( {\frac{{11}}{4} \times \frac{7}{{11}}} \right) \times \frac{4}{7} \times \frac{5}{3} = \frac{7}{4} \times \frac{4}{7} \times \frac{5}{3} = \frac{5}{3}\) |