Question

[Sao mà xxmangaka]

Tính nhanh :

1/5 x 19 x2/3 x10 x 1/2 x3 X 1/38

5/8 x 4 x 8/5 x 7 x 0,25 x 1/8

Answer 1

[Chung Yến Nhi]

a) 1/5 x 19 x 2/3 x 10 x 1/2 x 3 x 1/38

= ( 1/5 x 10 ) x ( 19 x 1/38 ) x ( 2/3 x 1/2 ) x 3

= ( 2 x 1/2 )  x ( 1/3 x 3 )

= 1 x 1

= 1

b) 5/8 x 4 x 8/5 x 7 x 0,25 x 1/8

= ( 5/8 x 8/5 ) x (4 x 0,25 ) x ( 7 x 1/8 )

= 1 x 1 x 7/8

= 7/8