3/5 x 8/27 x 5/3

= (3/5 x 5/3) x 8/27

= 1 x 8/27

= 8/27

3/5 x 8/27 x 5/3

= (3/5 x 5/3) x 8/27

= 1 x 8/27

= 8/27

=3/5*5/3*8/27=1*8/27=8/27

3/5x8/27x5/3

= 3/5x5/3x8/27

= 1 x 8/27

= 8/27

:))))

= 3/5 * 5/3 * 8/27

= 1 * 8/27

= 8/27

xin tiick

3/5x8/27x5/3

=(3/5x5/3)x8/27

=1x8/27=8/27

HT

1.   3/5 x 8/27 x 5/3                                          2.   7/19 x 1/3 + 7/19 x 2/3

= ( 3/5 x 5/3 ) x 8/27                                              = 7/19 x ( 1/3 + 2/3 )

= 1 x 8/27                                                              = 7/19 x 1

= 8/27                                                                    = 7/19

6/7 * 5/8*7/3*7/6*8/5

= 6*5*7*7*8 /7*8*3*6*5

=1*1*7*1*1/1*1*3*1*1

= 7/3 

3/5 x 8/27 x 5/3= 3/5 x 5/3 x 8/27= 8/27

7/19 x 1/3 + 7/19 x 2/3 = 7/19 x (1/3 + 2/3)= 7/19 x 1 = 7/19

3/5 x 8/27 x 5/3=8/27 vì 3/5 x 5/3 =1 

tương tự : 7/9x1/3x7/9x2/3=1/3x2/3=2/9

"Và" ở đây nghĩa là sao bạn nhỉ?

0,81x8,4+2,6x0,81

= 0,81x(8,4+2,6)

=0,81x11

=8,91

16,5x47,8+47,8x3,5

=47,8x(16,5+3,5)

=47,8x20

=956

nho h cho mk nhe 

a,     0,81 x 8,4 + 2,6 x 0,81

  = 0,81 x ( 8,4 + 2,6 )

  = 0,81 x      11

  = 8,91

b,   16,5 x 47,8 + 47,8 x 3,5

  =  47,8 x ( 16,5 + 3,5 )

  = 47,8 x       20

  = 956