12- ( 12 - 9,36 ) 

= 9,36 - ( 12 - 12 )

= 9,36 - 0

= 9,36

=12-12+9,36

=0+9,36

=9,36

a, ( 10 + 10 ) - ( 9,34 + 9 , 66 ) 

    = 20 - 19 

    = 1

b, 12 - 2 , 64

   = 9,36

a) =9,46
b) =45
c) =20,32
d) =34,9
 

Bài 2. Tính nhanh :
a) 12 – ( 12 – 9,36 )

= 12 - 2,64

= 9,36

b) 72,64 – 18,35 – 9,29

= 54,29 - 9,29

= 45

c) ( 10 – 9,34 ) + ( 10 + 9,66 )

= 0.66 + 19,66

= 20,32

d) 45,83 – 8,46 – 6, 54 + 4,17

= 37,37 - 10,71

= 26,66

( 10 - 9,34) + (10 - 9,66) = 0,66 +0,34 =1

12 - (12 - 9,36)= 12 -2,64 = 9,36

**** cho mink nhé

= 18,72 x6+9.36x2x2-4.68x4x3

=18.72x6+18.72x2-18.72x3

=18.72x(6+2-3)

=18.72x5

=93,6

\(18,72.6+9,36.4-4,68.12\)

\(=18,72.6+9,36.2.2-4,68.4.3\)

\(=18,72.6+18,72.2-18,72.3\)

\(=18,72\left(6+2-3\right)\)

\(=18,72.5=93,6\)

1.

( 10 - 9,34 ) + ( 10 - 9,66 )

= 0,66 + 0,34

= 1

12 - ( 12 - 9,36 ) 

= 12 - 2,64

= 9,36

38,52 + 0,302 x 100 - 0,72

= 38,52 + 30,2 - 0,72

= 68,72 - 0,72

= 68

2.

\(1-\left(5\frac{3}{8}+x-7\frac{5}{24}\right):16\frac{2}{3}=0\)

\(1-\left(\frac{43}{8}+x-\frac{173}{24}\right):\frac{50}{3}=0\)

\(\left(\frac{43}{8}+x-\frac{173}{24}\right):\frac{50}{3}=0+1=1\)

\(\left(x-\frac{151}{12}\right):\frac{50}{3}=1\)

\(x-\frac{151}{12}=1\times\frac{50}{3}\)

\(x-\frac{151}{12}=\frac{50}{3}\)

\(x=\frac{50}{3}+\frac{151}{12}\)

\(x=\frac{117}{4}\)

Bài 1

\(\left(10-9,34\right)+\left(10-9,66\right)\)

\(=0.66+0,34=1\)

\(12-\left(12-9,36\right)\)

\(=12-2.64=9,36\)

\(38,52+0,302.100-0,72\)

\(=38,52+30,2-0,72\)

\(=7.6\)

Bài 2

\(1-\left(5\frac{3}{8}+x-7\frac{5}{24}\right):16\frac{2}{3}=0\)

\(1-\left(\frac{43}{8}+x-\frac{173}{24}\right):\frac{50}{3}=0\)

\(\left(\frac{43}{8}+x-\frac{173}{24}\right):\frac{50}{3}=1\)

\(\frac{43}{8}+x-\frac{173}{24}=\frac{3}{50}\)

\(\frac{43}{8}+x=\frac{3}{50}+\frac{173}{24}\)

\(\frac{43}{8}+x=\frac{4361}{600}\)

\(x=\frac{142}{75}\)( gửi lại bài 2 đã )