sai đề rồi bạn ơi,ra số âm đó

a , 38 , 6 + 42 , 78 × 1 , 6 : 0 , 001 = 38 , 6 + 42 , 78 × 1600 = 38 , 6 + 68448 = 68486 , 6 b , 4 , 36 + 13 , 734 : 13 , 08 − 1 , 82 = 4 , 36 − 1 , 82 + 1 , 05 = 2 , 54 + 1 , 05 = 3 , 59

a)

38 , 6 + 42 , 78 × 1 , 6 : 0 , 001 = 38 , 6 + 42 , 78 × 1600 = 38 , 6 + 68448 = 68486 , 6

b)

4 , 36 + 13 , 734 : 13 , 08 − 1 , 82 = 4 , 36 − 1 , 82 + 1 , 05 = 2 , 54 + 1 , 05 = 3 , 59

\(\left(a\right)2,52:0,56\cdot7,2:2,5\)

\(=4,5\cdot7,2:2,5\)

\(=32,4:2,5=12,96\)

\(\left(b\right)4,36+13,734:13,08-2,716\)

\(=4,36+1,05-2,716\)

\(=5,41-2,716=2,694\)

\(\left(c\right)\frac{5}{13}\cdot\left(\frac{5}{20}-\frac{1}{10}\right)+\frac{2}{5}\)

\(=\frac{5}{13}\cdot\left(\frac{5}{20}-\frac{2}{20}\right)+\frac{2}{5}\)

\(=\frac{5}{13}\cdot\frac{3}{20}+\frac{2}{5}\)

\(=\frac{15}{260}+\frac{2}{5}=\frac{15}{260}+\frac{104}{260}\)

\(=\frac{119}{260}\)

Trả lời:

a, \(2,52\div0,56\times7,2\div2,5\)

\(=4,5\times7,2\div2,5\)

\(=32,4\div2,5\)

\(=12,96\)

b,\(4,36+13,734\div13,08-2,716\)

\(=4,36+1,05-2,716\)

\(=5,41-2,716\)

\(=2,694\)

c,\(\frac{5}{13}\times\left(\frac{5}{20}-\frac{1}{10}\right)+\frac{2}{5}\)

\(=\frac{5}{13}\times\frac{3}{20}+\frac{2}{5}\)

\(=\frac{3}{52}+\frac{2}{5}\)

\(=\frac{119}{260}\)

Đáp án là: 12,96 = 324/25

nhu the nao

2, 52 : 0, 56 x 7, 2 : 2, 5

=4, 5 x 7, 2 : 2 ,5

= 32, 4 : 2, 5

= 12,96 = 324/ 25

a.12,96

b,2,9998.....

c,10/113/156

a.

2,52 : 0,56. 7,2 :2,5

= 4,5 . 7,2 : 2,5

= 32,4 : 2,5

= 12,96

b.

\(\frac{5}{13}\times\left(\frac{54}{20}-\frac{1}{10}\right)+3\frac{2}{5}\)

= \(\frac{5}{13}\times\left(\frac{27}{10}-\frac{1}{10}\right)+\frac{17}{5}\)

= \(\frac{5}{13}\times\frac{13}{5}+\frac{17}{5}\)

= \(1+\frac{17}{5}=\frac{22}{5}\)

Tính giá trị của biểu thức:

a ) 2,52 : 0,56 . 7,2 :2,5

= 4,5 . 7,2 : 2,5

= 32,4 : 2,5

= 12,96

b )

\(\frac{5}{13}\)\(\times\)\(\left(\frac{54}{20}-\frac{1}{10}\right)\)\(+\)\(3\frac{2}{5}\)

\(=\)\(\frac{5}{13}\)\(\times\)\(\left(\frac{54}{20}-\frac{2}{20}\right)\)\(+\)\(\frac{17}{5}\)

\(=\)\(\frac{5}{13}\)\(\times\)\(\frac{52}{20}\)\(+\)\(\frac{17}{5}\)

\(=\)\(\frac{5}{13}\)\(\times\)\(\frac{13}{5}\)\(+\)\(\frac{17}{5}\)

\(=\)\(1\)\(+\)\(\frac{17}{5}\)

\(=\)\(\frac{22}{5}\)

1.Tìm X:

a)  `x : 8 = 107,8 - 29,25`

`x:8=78,55`

`x=78,55xx8`

`x=628,4`

b) `x + 16,7 = 50,5 : 2,5`

`x+16,7=20,2`

`x=20,2-16,7`

`x=3,5`

2.Tìm X:

a) `x - 2,35  =  3,6 : 4,5` 

`x-2,35=0,8`

`x=0,8+2,35`

`x=3,15`

b) `189,5 - x = 7,2 xx 14`

`189,5 - x = 100,8`

`x=189,5-100,8`

`x=88,7`

3. Tính giá trị biểu thức :

`13,5 : 4,5 xx 2,4 + (156,9 – 80,6) `

`=3xx2,4+76,3`

`=7,2+76,3`

`=83,5`

4. Tính giá trị biểu thức :

`1,25 xx 4,2 + 119,6 : 5,2 – 23,19`

`=5,25+23-23,19`

`=5,06`

5. Tính giá trị biểu thức :

`14,75 – 7,15 : 5 + 2,6 xx 3,5`

`=14,75 – 1,43 + 9,1`

`=22,42`

6. Tính nhanh

a) `3,6 xx 78 + 78 xx 6,4=78xx(3,6+6,4)=78xx10=780`

b) `80 xx 5,29 xx 1,25=(80xx1,25)xx5,29=100xx5,29=529`