Question

tính nhanh

6x7x8x9x10
phần
20x 18x 16x14x12

Answer 1

\(A=\frac{6.7.8.9.10}{12.14.16.18.20}=\frac{6.7.8.9.10}{6.2.7.2.8.2.9.2.10.2}=\frac{1}{2.2.2.2.2}=\frac{1}{32}\)

Answer 2

\(\frac{6\cdot7\cdot8\cdot9\cdot10}{20\cdot18\cdot16\cdot14\cdot12}=\frac{6}{12}\cdot\frac{7}{14}\cdot\frac{8}{16}\cdot\frac{9}{18}\cdot\frac{10}{20}=\frac{1}{2}\cdot\frac{1}{2}\cdot\frac{1}{2}\cdot\frac{1}{2}\cdot\frac{1}{2}=\left(\frac{1}{2}\right)^5=\frac{1}{32}\)

Answer 3

Ta có: \(\frac{6\cdot7\cdot8\cdot9\cdot10}{20\cdot18\cdot16\cdot14\cdot12}\)

\(=\frac{6}{12}\cdot\frac{7}{14}\cdot\frac{8}{16}\cdot\frac{9}{18}\cdot\frac{10}{20}\)

\(=\frac{1}{2}\cdot\frac{1}{2}\cdot\frac{1}{2}\cdot\frac{1}{2}\cdot\frac{1}{2}=\frac{1}{32}\)

Answer 4

\(\frac{6\times7\times8\times9\times10}{20\times18\times16\times14\times12}\)

\(=\frac{1}{2^5}=\frac{1}{32}\)