a. 7 . 10 > 0

b. 123 . 8 > 12 . 31

c. 15 . 28 < 22 . 27

d. 17 . 3 > 23 . 2 

HT nha^^

7.0  >  0                      123.8  > 12.31                     15.28  <  22.27                         17.  > 23.2

a,3/5.(5+12+1/3)

=3/5.52/3

=52/5

b,=3/5.5/3.3/4

=1.3/4

=3/4

Anh tính thẳng ra luôn nhé.

a. 3/5 x 5 + 12 x 3/5 + 3 : 5/3 = 12

b. 3/5 x 45/27 x 135/180 = 3/4

a. 3/5 x 5 + 12 x 3/5 + 3 : 5/3

= 3/5 x 5 + 12 x 3/5 + 3 x 3/5

= 3/5 x ( 5 + 15 + 3)

= 3/5 x 20

= 12

b. 3/5 x 45/27 x 135/180

= 3/5 x 5/3 x 3/4

= 1 x 3/4

= 3/4

a)x-3/4=5/12 : 10/3

x-3/4= 1/8

x = 1/8 + 3/4

x = 7/8

b)7/6 - x=3/5 x 15/18

7/6 - x = 1/2

x = 7/6 - 1/2

x = 2/3

a)x-3/4=5/12 : 10/3

x-3/4= 1/8

x = 1/8 + 3/4

x = 7/8

b)7/6 - x=3/5 x 15/18

7/6 - x = 1/2

x = 7/6 - 1/2

x = 2/3

b: =>x-4=-4

hay x=0

12 : 3 = 4 x 4 = 16

20 x 3 = 60

90 : 1 = 90

123 - 123 = 0

10 x 9 = 90 : 9 = 10

12 - 9 = 3 x 9 = 27

23 - 5 = 18

123 + 12 = 135

1000 - 200 = 800

333 - 111 = 222

\(20.3=60\)

\(90.1=90\)

\(123-123=0\)

\(10.9=\frac{810}{9}=90\)

\(23-5=15\)

\(123+12=135\)

\(1000-200=800\)

\(333-111=222\)

`@` `\text {Ans}`

`\downarrow`

`a)`

`5(x + 35) = 515`

`=> x + 35 = 515 \div 5`

`=> x+ 35 = 103`

`=> x = 103 - 35`

`=> x = 68`

Vậy, `x = 68`

`b)`

`12x - 33 = 3^2 * 3^3`

`=> 12x - 33 = 3^5`

`=> 12x = 3^5 + 33`

`=> 12x = 276`

`=> x = 276 \div 12`

`=> x = 23`

Vậy, `x = 23`

`c)`

`6x - 5 = 19`

`=> 6x = 19 + 5`

`=> 6x = 24`

`=> x = 24 \div 6`

`=> x = 4`

Vậy, `x = 4`

`d)`

`4(x - 12) + 9 = 17`

`=> 4(x - 12) = 17 - 9`

`=> 4(x - 12) = 8`

`=> x - 12 = 8 \div 4`

`=> x - 12 = 2`

`=> x = 14`

Vậy, `x = 14`

`e)`

123 - 5(x + 4) = 38`

`=> 5(x + 4)= 123 - 38`

`=> 5(x + 4) =85`

`=> x + 4 = 85 \div 5`

`=> x + 4 = 17`

`=> x = 13`

Vậy, `x = 13`

`f)`

`(3x - 2^4) * 7^3 = 2 * 7^4`

`=> 3x - 2^4 = 2 * 7^4 \div 7^3`

`=> 3x - 2^4 = 2* 7`

`=> 3x - 2^4 = 14`

`=> 3x = 14 + 2^4`

`=> 3x = 30`

`=> x = 30 \div 3`

`=> x = 10`

Vậy, `x = 10.`

a,\(\frac{5}{8}\times0=0\)

b.\(\frac{8}{21\times1}\)=\(\frac{8}{21}\)