a) = 8 . 15 - [115- 7² ]

     = 8 . 15 - [115- 49 ]

     = 120    - 56

      = 64

b) = 100 : {250 : [450 - (2.125 - 8.25)]}

    = 100 : {250 : [450 - (250 - 200 )]}

     = 100 : {250 : [450 - 50]}

     = 100 : {250 :400}

     = 100 : 0,265

      = 0,00265

     = 

\(a,2^3.15-\left[115-\left(12-5\right)^2\right]\)

\(=8.15-\left[115-\left(12-5\right)^2\right]\)

\(=120-\left[115-7^2\right]\)

\(=120-\left[115-49\right]\)

\(=120-66\)

\(=54\)

\(b,100:\left\{250:\left[450-\left(2.5^3-2^3.25\right)\right]\right\}\)

\(=100:\left\{250:\left[450-\left(2.125-8.25\right)\right]\right\}\)

\(=100:\left\{250:\left[450-\left(250-200\right)\right]\right\}\)

\(=100:\left\{250:\left[450-50\right]\right\}\)

\(=100:\left\{250:400\right\}\)

\(=100:0,625\)

\(=160\)

a: \(2^3\cdot15-\left[115-\left(12-5\right)^2\right]\)

\(=8\cdot15-115+7^2\)

\(=54\)

b: \(100:\left\{250:\left[450-\left(2\cdot5^3-2^3\cdot25\right)\right]\right\}\)

\(=100:\left\{250:\left[450-50\right]\right\}\)

\(=100:\left\{250:400\right\}\)

\(=100:\dfrac{5}{8}=160\)

a,  600 : { 450 : 450 - 4 . 5 3 - 2 3 . 5 2 }

= 600:{450:[450 - (4.125 - 8.25)]} = 600:{450:[450 - (500 - 200)]}

= 600:{450:[450 - 300]} = 600:{450:150} = 600:3 = 200

b,  18 . { 420 : 6 - 150 - ( 68 . 2 - 2 3 . 5 ) }

= 18.{70 - [150 - (68.2 - 8.5)]} = 18.{70 - [150 - (136 - 40)]}

= 18.{70 - [150 - 96]} = 18.{70 - 54} = 18.16 = 288

\(a,\left\{\left[\left(37+13\right):5\right]-45:5\right\}.7\)

\(=\left\{\left[50:5\right]-45:5\right\}.7\)

\(=\left\{10-45:5\right\}.7\)

\(=\left\{10-9\right\}.7\)

\(=1.7=7\)

\(6^2.10:\left\{780:\left[10^3-\left(2.5^3+35.14\right)\right]\right\}\)

\(=36.10:\left\{780:\left[1000-\left(2.125+35.14\right)\right]\right\}\)

\(=360:\left\{780:\left[1000-\left(250+490\right)\right]\right\}\)

\(=360:\left\{780:\left[1000-740\right]\right\}\)

\(=360:\left\{780:260\right\}\)

\(=360:3=120\)

295   - ( 31   - 2 2 . 5 ) 2 = 295 − 11 2 = 174

1,

=66

2,

=28

3,

=2016+450-2016

=450

4, 

=360-360+111

=111

5,

=1972-638-972

=1972-972-638

=362

1) = 27 + 37 + 2

= 64 + 2 = 66

2) = 6 + 26 - 4 = 32 - 4 = 28

3) = (2016-2016)+450 = 450

4) =(364-364)+111 = 111

5) = (1972-972)-638 = 1000 - 638 = 362

1. 5 + 22 + 37 + 2

= 27 + 39

= 66

2. 12 - 6 + 26 - 4

= 6 + 22

= 28

3. (2016 + 450) - 2016

= 2016 + 450 - 2016

= 2016 - 2016 + 450

= 450

4. 364 - (364 - 111)

= 364 - 364 + 111

= 0 + 111

= 111

5. 1972 - (638 + 972)

= 1972 - 638 - 972

= 1972 - 972 - 638

= 1000 - 638 

= 362

a)  20 : 2 2 − 5 9 : 5 8 = 5 − 5 = 0

b)  ( 5 19 : 5 17 − 4 ) : 7 0 = ( 5 2 − 4 ) : 1 = 21

c)  295 − ( 31 − 2 2 .5 ) 2 = 295 − 11 2 = 174

a 20:2^2 -5^9:5^8

= 20:4 - 5^1

=5-5

=0

a)  20 : 2 2 − 5 9 : 5 8 = 5 − 5 = 0.

b)  ( 5 19 : 5 17 − 4 ) : 7 0 = ( 5 2 − 4 ) : 1 = 21.

c)  295 − ( 31 − 2 2 .5 ) 2 = 295 − 11 2 = 174.

;)

a ) 150 + 225 + 450 

Có :

150 chia hết cho 15 ; 3

225 chia hết cho 15 ; 3

450 chia hết cho 15 ; 3

Vậy tổng trên chỉ chia hết cho 15 ; 3 và ko chia hết cho 2 ; 9 ; 18

b ) Hiệu trên có tận cùng là số chẵn

=> hiệu trên chia hết cho 2

28422 chia hết cho 9 ; 18 ; 3

22050 chia hết cho 3 ; 9 ; 18

Vậy hiệu trên chia hết cho 3 ; 2 ; 9 ; 18 và ko chia hết cho 15

450.(-2) = -900