A = 78 x 31 + 78 x 24 + 78 x 17 + 22 x 72

A = 78 x ( 31 + 24 + 17 ) + 22 x 72

A = 78 x 72 + 22 x 72

A = 72 x ( 78 + 22 ) 

A = 72 x 100

A = 7200

C = 53 x 39 + 47 x 39 - 53 x 21 - 47 x 21

C = 39 x ( 53 + 47 ) - 21 x ( 53 - 47 )

C = 39 x 100 - 21 x 6

C = 3900 - 126

C = 3774

ko pc tui thua bn 1 lp 

A = 78 x 31 + 78 x 24 + 78 x 17 + 22 x 72

A = 78 x ( 31 + 24 +17 ) + 22 x 72

A = 78 x 72 + 22 x 72

A = 72 x ( 78 + 22 )

A = 72 x 100

A = 7200

Bài 1 :

a) \(...=45\left(56+44\right)-500=45.100-500=4500-500=4000\)

b) \(...=3^2.6-6^{18}+1=45+1-6^{18}=46-6^{18}\)

c) \(...=756\left(66+48-14\right)=756.100=75600\)

d) \(...=8.15-\left(149-7^2\right)=120-\left(149-49\right)=120-100=20\)

Bài 2 :

a) \(x-21=46\Rightarrow x=21+46\Rightarrow x=87\)

b) \(2^x.4=128\Rightarrow2^x=32\Rightarrow2^x=2^5\Rightarrow x=5\)

c) \(3x+27=162\Rightarrow3x=162-27\Rightarrow3x=135\Rightarrow x=45\)

d) \(4x-8=4^{2023}.4^{2021}\)

\(\Rightarrow4x-8=4^{2023+2021}\)

\(\Rightarrow4x-8=4^{4044}\)

\(\Rightarrow4x=4^{4044}+8\)

\(\Rightarrow x=\left(4^{4044}+8\right):4\)

\(\Rightarrow x=4^{4043}+2\)

Bài 3 :

Số học sinh góp 20000 đồng là :

\(35-\left(1+3\right)=31\left(hsinh\right)\)

Tổng số tiền lớp 6a ủng hộ là :

\(1.100000+3.40000+31.20000=840000\left(đồng\right)\)

Đáp số...

là biếng viết lời giải

1062

3700

40340

còn lời giải  thích thì hỏi sau

a)997+86=997+3+83=1000+83=1083

b)37.(38+62)=37.100=3700

c)27.332+68.27+73.332+68.78

=27.332+73.332+68.27+68.78

=332.(27+73)+68.(27+78)

=332.100+68.105

=40340

tớ trả lời đầy đủ sao ko ****?

a) `123 - 27 + 27 + 13 - 123`

`= (123 - 123) + (27 - 27) + 13`

`= 0 + 0 + 13`

`= 13`

`---`

b) `175 + 25 + 13 + 15 - 175 - 25`

`= (175-175)+(25-25)+25+13`

`=0+0+25+13`

`=28`

`---`

c) \(53\times39+47\times39+53\times21+47\times21\)

\(=\text{[}\left(53+47\right)\times39]+\left[\left(53+47\right)\times21\right]\)

\(=\left(100\times39\right)+\left(100\times21\right)\)

\(=3900+2100\)

`=6000`

`---`

d) \(49\times35+49\times16-49\times61\)

`=` \(49\times\left(35+16-61\right)\)

`=` \(49\times\left(-10\right)\)

`=-490`

a) (-37) + 15 - 30
  =     (-22)    - 30
  =    (-22) + (-30)
  =        -52
b) -25 - 30 - 35
  = -25 + (-30) + (-35)
  = -55 + (-35)
  =      -90
c) 27 - 7 x (-3)
  = 27 - (-21)
  = 27 + 21
  =    48
d) -15 x 5 + 17 - 6 x 4
  = -75 + 17 - 24
  =     -58 - 24
  =   -58 + (-24)
  =      -82

a)   (-37) + 15 - 30 = -52

b)    - 25 - 30 - 35=-90

c)     27 - 7 x ( - 3 ) = 48

d)    - 15 x 5 + 17 - 6 x 4 = -82

a) -52

b) -90

c) 48

d ) -82

a) 2010 - 2000 : [486 - 2(7² - 6)]

=  2010 - 2000 : [486 - 2(49 - 6)]

=  2010 - 2000 : [486 - 2 . 43]

=  2010 - 2000 : [486 - 86]

=  2010 - 2000 : 400

=  2010 - 5

= 2005

b) 2345 - 1000 : [19 - 2(21 - 18)² ]

=  2345 - 1000 : [19 - 2 . 3² ]

=  2345 - 1000 : [19 - 18]

=  2345 - 1000 : 1

=  2345 - 1000

=  1345

c) 128 - [68 + 8(37 - 35)² ] : 4

=  128 - [68 + 8 . 2² ] : 4

=  128 - [68 + 32 ] : 4

=  128 - 100 : 4

=  128 - 25

=  103

d) 568 - {5[143 - (4 - 1)²  ] + 10} : 10

=  568 - {5[143 - 9 ] + 10} : 10

=  568 - {5 . 134 + 10 } : 10

=  658 - {670 + 10 } : 10

=  658 - 680 : 10

=  658 - 68

=  590

A. 122

B.256

C.23

e: \(=128-\left[68+8\cdot4\right]:4=128-25=103\)

\(a.3.5^2+15.2^2-26:2\)                     \(b.5^3.2-100:4+2^3.5\)

\(=75+60-13\)                                  \(=250-25+40\)   

\(=135+13=148\)                                \(=265\)

\(c.6^2:9+50.2-3^3.3\)                \(d.2345-1000:\left[19-2.\left(21-18\right)^2\right]\)

\(=4+100-81\)                            \(=2345-1000:\left[19-2.3^2\right]\)

\(=23\)                                            \(=2345-1000:\left[19-18\right]\)

                                                    \(=2345-1000:1\)

                                                    \(=2345-1000=1345\)

\(e.128-\left[68+8.\left(37-35\right)^2\right]:4\)               

\(=128-\left[68+8.2^2\right]:4\)

\(=128-\left[68+32\right]:4\)

\(=128-100:4\)

\(=128-25=103\)

\(f.568-\left\{5.\left[143-\left(4-1\right)^2\right]+10\right\}:10\)

\(=568-\left\{5.\left[143-3^2\right]+10\right\}:10\)

\(=568-\left\{5.134+10\right\}:10\)

\(=568-\left\{670+10\right\}:10\)

\(=568-680:10\)

\(=568-68=500\)