=7,15(2+9-1)=71,5

150 x 57 : 15

= (150:15) x 57

= 100 x 57

= 5700

46 x 77 : 11

= 46 x ( 77 : 11)

= 46 x 7

= 322

\(150x57:15=\left(150:15\right)x57=10x57=570\)

\(46x77:11=46x\left(77:11\right)=46x7=322\)

4,52:9-1,46:9=(4,52-1,46):9=3,06:9=0,34.

4,52:9 - 1,46 : 9

= (4,52 - 1,46):9

= 3,06:9=0,34

`4,52 : 9-1,46:9`

`=(4,52 - 1,46) : 9`

`=3,06 : 9 `

`= 0,34`

12121212 : 12 = 10101

= 1010101

12121212 : 12 = 1010101 tính bình thường mà

đề đk ạ

thiếu dấu bn ơi:v

\(a.4,7\text{×}5,5-4,7\text{×}4,5\\ =4,7\text{×}\left(5,5-4,5\right)\\ =4,7\text{×}1=4,7\\ b.9,8\text{×}x=6,2\text{×}9,8\\ x=6,2\text{×}9,8:9,8\\ x=6,2\text{×}1\\ x=6,2\)

\(\dfrac{3}{7}+\dfrac{6}{11}+\dfrac{5}{11}\)
\(=\dfrac{3}{7}+\left(\dfrac{6}{11}+\dfrac{5}{11}\right)\)
\(=\dfrac{3}{7}+1\)
\(=\dfrac{3}{7}+\dfrac{7}{7}\)
\(=\dfrac{10}{7}\)

\(\left(\dfrac{1}{2}+\dfrac{1}{4}\right)\times\left(9\times5-5\times9\right)=\left(\dfrac{1}{2}-\dfrac{1}{4}\right)\times0=0\)

( \(( \dfrac{1}{2} + \dfrac{1}{4}) . ( 45 - 45 ) =( \dfrac{1}{2} + \dfrac{1}{4}) . 0 = 0 \)

dấu chấm  . này là nhân nha

`7/9+9/7+6/9+11/7`

`=(7/9+6/9)+(9/7+11/7)`

`=13/9+20/7`

rồi thuận tiện  nào cái bài này=)

= ( 7/9 + 6/9 ) + ( 9/7 + 11/7 ) 

= 13/9 + 20/7

= 271/63