Question

Tính nhanh:

\(\frac{1^2}{1.2}.\frac{2^2}{2.3}.\frac{3^2}{3.4}.\frac{4^2}{4.5}.\frac{5^2}{5.6}\)

Answer 1

1/6 nhe

Answer 2

\(=\frac{1}{6}\)

Answer 3

\(\frac{1^2}{1\cdot2}\cdot\frac{2^2}{2\cdot3}.\frac{3^2}{3\cdot4}\cdot\frac{4^2}{4\cdot5}\cdot\frac{5^2}{5\cdot6}\)

\(=\frac{1\cdot1\cdot2\cdot2\cdot3\cdot3\cdot4\cdot4\cdot5\cdot5}{1\cdot2\cdot2\cdot3\cdot3\cdot4\cdot4\cdot5\cdot5\cdot6}\)

\(=\frac{1}{6}\)

Answer 4

1/6 k mk nha

Answer 5

Cách làm:

\(\frac{1x1x2x2x3x3x4x4x5x5}{1x2x2x3x3x4x4x5x5x6}\)

\(=\frac{1}{6}\)

                              \(ĐS:\frac{1}{6}\)

Answer 6

      \(\frac{1^2}{1.2}.\frac{2^2}{2.3}.\frac{3^2}{3.4}.\frac{4^2}{4.5}.\frac{5^2}{5.6}\)

\(=\frac{1.1.2.2.3.3.4.4.5.5}{1.2.2.3.3.4.4.5.5.6}\)

\(=\frac{1}{6}\)

Answer 7

\(\frac{1^2}{1.2}.\frac{2^2}{2.3}.\frac{3^2}{3.4}.\frac{4^2}{4.5}.\frac{5^2}{5.6}\)

\(=\frac{1^2.2^2.3^2.4^2.5^2}{1.2.2.3.3.4.4.5.5.6}\)

\(=\frac{\left(1.2.3.4.5\right)\left(1.2.3.4.5\right)}{\left(1.2.3.4.5\right)\left(2.3.4.5.6\right)}\)

\(=\frac{1}{6}\)