a) 86*(121-120+9)==86*10=860

b)136*(75+19+6)=136*100=13600

Mk giải r đó nha chắc chắn đúng

chao ban! Day la cau tra loi cua mh!

a,86*121-86*120+86*9

=86*(121-120+9)

=86*10

=860

b,136*75+136*19+136*6

=136*(75+19+6)

=136*100

=13600

Chuc ban hoc tot!!!

a)86 x (121-120+9)=860

b)136 x (75+19+6)=13600

Câu 3:

a: (x-5):2=7

=>x-5=14

hay x=19

b: 86-(5x+3)=38

=>5x+3=48

=>5x=45

hay x=9

41 x 36 + 59 x 90 + 41 x 84 + 59 x 30

= 41 x (36 + 84) + 59 x ( 90 + 30 )

= 41 x 120 + 59 x 120

= 120 x ( 41 + 59 )

= 120 x 100

= 12000

4 x 51 x 7 + 2 x 86 x 7 + 12 x 2 x 7

= 7 x ( 51 x 4 + 86 x 2 + 12 x 2 )

= 7 x ( 204 + 172 + 24 )

= 7 x 400

=2800

41x 36 +59 x 90 +41 x84 +59 x 30

  =41x (36+84) +59 x (90+30)

  =41 x 120 + 59x 120

  =120 x (41+59)

  =120x 100

  =12000

4x 51 x 7 + 2 x 86 x 7 + 12 x 2 x 7

  =7x (51 x 4 + 86 x 2 - 12 x 2 )

  =7x ( 204+ 172 + 24 )

  = 7x 400

 =2800

Ta có:

41 x 36 + 59 x 90 + 41 x 84 + 59 x 30

= 41 x (36+84) + 59 x (30+90)

=41 x 120+59 x 120

=(41+59) x 120=100 x 120=12000

4 x 51 x 7 + 2 x 86 x 7 + 12 x 2 x 7

=2 x 7 x (51 x 2+86+12)

=14 x 200

=2800

Câu 2:

a: x-158=32

=>x=158+32

=>x=190

b: \(x\cdot24=264\)

=>\(x=\dfrac{264}{24}\)

=>x=11

c: \(6x+9=3^7:3^4\)

=>\(6x+9=3^3\)

=>6x+9=27

=>6x=18

=>x=18/6=3

Câu 1:

a: \(86\cdot19+14\cdot19\)

\(=19\left(86+14\right)\)

\(=19\cdot100=1900\)

b: \(4\cdot\left(-5\right)^2-104\cdot\left(-5\right)^2\)

\(=4\cdot25-104\cdot25\)

\(=25\left(4-104\right)=-100\cdot25=-2500\)

c: \(7\cdot\left(-2\right)\cdot8\left(-5\right)\)

\(=7\cdot2\cdot8\cdot5\)

\(=56\cdot10=560\)

d: \(59-\left[59+\left(-76\right)\right]\)

\(=59-59+76\)

=76

xin hãy giúp mik ik

a, 8600
b, 5000

86x121-86x22+86=
 86x121-86x22+86x1=
  86x(121-22+1)|=
   86x100=8600
25x191-100+25x13=
25x191-25x4+25x13=
25x(191-4+13)=
25x200=5000

a) (25x32) : 8           

= 25 x (4 x 8) : 8

= (25 x 4) x (8:8)

= 100 x 1

=100

b, 24 x 11 + 6 x 86 x 4 + 72

= 24 x 11 + (6 x 4) x 86 + 24 x 3

= 24 x 11 + 24 x 86 + 24 x 3

= 24 x (11+86+3)

= 24 x 100

= 2 400

\(\left(25\times32\right):8=25\times32:8=25\times\left(32:8\right)=25\times4=100\\ 24\times11+6\times86\times4+72\\ =24\times11+24\times86+24\times3\\ =24\times\left(11+86+3\right)\\ =24\times100=2400\\ 36\times5+9\times79\times4+72\times8\\ =36\times5+36\times79+36\times16\\ =36\times\left(5+79+16\right)\\ =36\times100=3600\\ \left(56\times125\right):7=56\times125:7=\left(56:7\right)\times125=8\times125=1000\)

a.(64 - 32 ) :8 = 32 : 8 = 4 

b. 36 x 2 x7 + 36 x 86

= 36 x (14 + 86)

= 36 x 100

= 3600

   68:8 - 32 : 8

= ( 68 - 32): 8

=    36 : 8

=    4,5

72 x 7 + 36 x 86

= 72 x 7 + 36 x 2 x 43

= 72 x 7 + 72 x 43

= 72 x ( 7 + 43)

= 72 x 50

= 3600

a) 64 : 8 - 32 : 8

=( 64 - 32 ) : 8 

=      32      :  8

=         4

b. 36 x 2 x7 + 36 x 86

= 36 x (14 + 86)

= 36 x 100

= 3600

123,45 + 23,56 +76,44 + 54,55

= (123,45 + 54,55) + (23,56 + 76,44)

= 178 + 100

= 278

456 x 45 + 456 x 10 + - 456 x 55

=456 x (45 +10-55)

=456 x 0

=0

2,5 x 8,5 + 7,5 x 8,5 

=8,5 x (2,5 +7,5)

= 8,5 x 10

= 85

86 x 5 + 86 x 4 + 86

= 86 x (5+4+1)

= 86 x10

860

25 x 8 x 17 x 50

= 50 x 4 x 17 x 50

= 200 x 17 x 50 

= 200 x 50 x 17

= 10000 x 17

= 170000

(12 x 2 + 12 x 4 - 12 x 6 ) : ( 2 + 4 + 6 +... + 12 +14)

=(12 x (2 + 4 - 6) ) : ( 2 + 4 + 6 + ... + 12 + 14 )
= (12 x 0 ) : (2 + 4 + 6 + ... + 12 + 14 )

=0 : ( 2 + 4 + 6 + ... + 12 + 14)

= 0

Bài 1: 

a: =83363

a. 86 x 121 - 86 x 22 + 86

= 86 x ( 121 - 22 + 1 )

= 86 x 100

= 8600

b. 25 x 191 - 100 + 25 x 13

= 25 x 191 - 25 x 4 + 25 x 13

= 25 x ( 191 - 4 + 13 )

= 25 x 200

= 5000

Tính giá trị biểu thức:

a. 794 x 105 - 105 : 15

b. 7102 - (1131 - 56) x 4

Tìm x:

a. 86 x 121 - 86 x 22 + 86

= 86 x ( 121 - 22 + 1 )

= 86 x 100

= 8600

b. 25 x 191 - 100 + 25 x 13

= 25 x 191 - 25 x 4 + 25 x 13

= 25 x ( 191 - 4 + 13 )

= 25 x 200

= 5000

Tính nhanh

a. 86 x 121 - 86 x 22 + 86

b. 25 x 191 - 100 + 25 x 13