Question

Tính bằng cách hợp lí nhất

A, 18/11 x 22/19 z 38/9     

B, 4/7 x 2/5 + 2/5 x 9/7 + 8/7 x 2/5

Answer 1

z là gì vậy bn

Answer 2

Answer 3

A ) \(=\dfrac{2\times9\times11\times2\times19\times2}{11\times19\times9}=\dfrac{8}{1}=8\)

b)\(=\dfrac{2}{5}\times\left(\dfrac{4}{7}+\dfrac{9}{7}+\dfrac{8}{7}\right)=\dfrac{2}{5}\times\dfrac{21}{7}=\dfrac{2}{5}\times3=\dfrac{6}{5}\)

Answer 4

a,18/11.38/9.22/19

=76/11.22/19

=8

b,2/5.(4/7+9/7+8/7)

=2/5.3

=6/5