Question

 \(\dfrac{8.9-4.15}{12.7-180}\)

\(\dfrac{^{2^3}.3}{2^2.3^2.5}\)

Answer 1

a) Ta có: \(\dfrac{8\cdot9-4\cdot15}{12\cdot7-180}\)

\(=\dfrac{4\cdot18-4\cdot15}{12\cdot7-12\cdot15}\)

\(=\dfrac{4\cdot\left(18-15\right)}{12\cdot\left(7-15\right)}\)

\(=\dfrac{4\cdot3}{12\cdot\left(-8\right)}\)

\(=\dfrac{12}{12\cdot\left(-8\right)}=\dfrac{-1}{8}\)

b) Ta có: \(\dfrac{2^3\cdot3}{2^2\cdot3^2\cdot5}\)

\(=\dfrac{2^2\cdot2\cdot3}{2^2\cdot3\cdot3\cdot5}\)

\(=\dfrac{2}{3\cdot5}=\dfrac{2}{15}\)

Answer 2

=2