TL:

=2,8×1,25+1,25×7,2=1,25×(2,8+7,2)=1,25×10=12,5

_HT_

Tham Khảo:

https://olm.vn/hoi-dap/detail/62824771750.html

+) 9,65 x 0,4 x 2,5

= 9,65 x ( 0,4 x 2,5 )

= 9,65 x 1

= 9,65

+) 7,38 x 1,25 x 80

= 7,38 x (1,25 x 80)

= 7,38 x 100

= 738

+) 0,25 x 40 x 9,84

= 10 x 9,84

= 98,4

+) 34,3 x 5 x 0,4

= 34,3 x 2

= 68,6

9,65 x 0,4 x 2,5

= 9,65 x 1

= 9,65

7,38 x 1,25 x 80

= 7,38 x 100

= 738

0,25 x 40 x 9,84

= 9,84 x 10

= 98,4

34,3 x 5 x 0,4

= 34,3 x 2

= 68,6

a) \(6,25+8,75+3,75+1,25=6,25+3,75+8,75+1,25=10+10=20\)

b) \(7,15:0,5+7,15x9-7,15=7,15x\left(1:0,5+7,19-1\right)=7,15x\left(2+9-1\right)=7,15x10=71,5\)

`@` `\text {Ans}`

`\downarrow`

`a)`

`6,25 + 8,75 + 3,75 + 1,25 `

`= (6,25 + 3,75) + (8,75 + 1,25)`

`= 10 +10 = 20`

`b)`

` 7,15 \div 0,5 + 7,15 \times 9 - 7,15 `

`= 7,15 \times 2 + 7,15 \times 9 - 7,15 \times 1`

`= 7,15 \times ( 2+ 9 - 1)`

`= 7,15 \times 10`

`= 71,5`

2/5+11/9+3/5+7/9= (2/5+3/5)+(11/9+7/9)                             = 1+2                             = 3

9/5 + 4/7 + 6/5 + 3/7

=  ( 9/5 + 6/5 ) + ( 4/7 + 3/7)

=            3        + 1

=        4

9/5 + 4/7 + 6/5 + 3/7 = (9/5 + 6/5) + (4/7 + 3/7)

= 15/5 + 7/7

= 3 + 1

= 4

1/2 x 45/33 x 1/9 x 11/6 = (1/2 x 1/9) x (45/33 x 11/6)

= 1/18 x 45/18

= 5/2

1/2 x 45/33 x 1/9 x 11/6

= (1/2 x 1/9) x (45/33 x 11/6)

= 1/18 x 45/18

= 5/2

ta có : (1,25 x 3,6) : (9.5)                  

          =1,25:5 x 3,6:9                                          

          = 0,25 x 0,4

          =0,1

=4,5 : 45

=0,1

tk nha

(1,25 x 3,6) : (9 x 5)

= 4,5 : 45

=  0,1

\(\Rightarrow x\times\left(\dfrac{9}{5}+\dfrac{6}{5}\right)=\dfrac{3}{4}\\ \Rightarrow x\times3=\dfrac{3}{4}\\ \Rightarrow x=\dfrac{3}{4}:3\\ \Rightarrow x=\dfrac{3}{4}\times\dfrac{1}{3}=\dfrac{1}{4}\)

\(\dfrac{9}{5}\times x+\dfrac{6}{5}\times x=\dfrac{3}{4}\)

\(x\times\left(\dfrac{9}{5}+\dfrac{6}{5}\right)=\dfrac{3}{4}\)

\(x\times3=\dfrac{3}{4}\)

\(x=\dfrac{3}{4}:3=\dfrac{3}{4}\times\dfrac{1}{3}\)

\(x=4\)

Sửa kết quả:

\(x=\dfrac{1}{4}\)

a.\(\dfrac{2}{3}\times\dfrac{4}{9}+\dfrac{2}{3}\times\dfrac{5}{9}=\dfrac{2}{3}\times\left(\dfrac{4}{9}+\dfrac{5}{9}\right)=\dfrac{2}{3}\times1=\dfrac{2}{3}\)

b.\(\dfrac{7}{5}\times\dfrac{3}{4}-\dfrac{1}{2}\times\dfrac{3}{4}=\dfrac{3}{4}\times\left(\dfrac{7}{5}-\dfrac{1}{2}\right)=\dfrac{3}{4}\times\dfrac{9}{10}=\dfrac{27}{40}\)

c.\(\left(\dfrac{5}{6}+\dfrac{5}{8}\right)\times\dfrac{2}{3}=\dfrac{35}{24}\times\dfrac{2}{3}=\dfrac{35}{36}\)

a) 2/3 x 4/9 + 2/3 x 5/9 

=2/3 x ( 4/9 + 5/9)

= 2/3 x 1

=  2/3

b, 7/5 x 3/4 - 1/2 x 3/4

= ( 7/5 - 1/2 ) x 3/4

=     9/10         x 3/4

=         21/40

c, ( 5/6 + 5/8 ) x 2/3       

 =      35/24 x 2/3

=       35/36

a) \(\dfrac{2}{3}\times\dfrac{4}{9}+\dfrac{2}{3}\times\dfrac{5}{9}=\dfrac{2}{3}\times\left(\dfrac{4}{9}+\dfrac{5}{9}\right)=\dfrac{2}{3}\times1=\dfrac{2}{3}\)

b) \(\dfrac{7}{5}\times\dfrac{3}{4}-\dfrac{1}{2}\times\dfrac{3}{4}=\left(\dfrac{7}{5}-\dfrac{1}{2}\right)\times\dfrac{3}{4}=\dfrac{9}{10}\times\dfrac{3}{4}=\dfrac{27}{40}\)

c) \(\left(\dfrac{5}{6}+\dfrac{5}{8}\right)\times\dfrac{2}{3}=\left(\dfrac{20}{24}+\dfrac{15}{24}\right)\times\dfrac{2}{3}=\dfrac{35}{24}\times\dfrac{2}{3}=\dfrac{35}{36}\)