Question

Tính bằng cách thuận tiện: a)2/5x3/4x5/6:3/4                b)123x145+100/145x135-45

 

Answer 1

a: \(=\dfrac{2}{5}\cdot\dfrac{5}{6}\cdot\dfrac{3}{4}\cdot\dfrac{4}{3}=\dfrac{2}{6}=\dfrac{1}{3}\)

b: \(=\dfrac{123\cdot145+100}{123\cdot145+12\cdot145-45}=\dfrac{123\cdot145+100}{123\cdot145+1695}\)

=3587/3906