a. 64 x 25 + 35 x 25 + 25

= 64 x 25 + 35 x 25 + 25 x 1

= 25 x ( 64 + 35 + 1 )

= 25 x 100 

= 2500

b. 58 x 42 + 32 x 8 + 5 x 16

c. ( 42 x 43 + 57 x 43 + 43 ) - 360 : 4

= 42 x 43 + 57 x 43 + 43 x 1 - 90

= 43 x ( 42 + 57 +1 ) - 90

= 43 x 100 - 90

= 4300 - 90

= 4210

d. 456 : 2 x 181456 : 3 - 102

Trả lời:

a,\(64\times25+35\times25+25\)

\(=25\times\left(64+35+1\right)\)

\(=25\times100\)

\(=2500\)

b,\(58\times42+32\times8+5\times16\)

\(=2436+256+80\)

\(=2772\)

c,\(\left(42\times43+57\times43+43\right)-360\div4\)

\(=43\times\left(42+57+1\right)-90\)

\(=43\times100-90\)

\(=4300-90\)

\(=4210\)

d,\(456\div2\times181456\div3-102\)

\(=228\div3\times181456-102\)

\(=76\times181456-102\)

\(=13790656-102\)

\(=13790554\)

a,64 x 25 + 35 x 25 +25

=25x(64+35+1)

=25x100

=250

b, 58 x 42 +32 x 8 +5 x 16

=2772

c,(42 x 43 +57 x 43+43 )-360:4

=43x(42+57+1) - 360 :4

= 43 x 100 -90

=4300-90

=4210

d,456:2 x 181456:3 -102

=228x181456:3-102

=13790656-102

=13790554

(3,2 + 1,6 ) x 2 x 1,8

=17,28

a, (3,2 + 1,6) x 2 x 1,8

= 4,8 x 2 x 1,8

= 9,6 x 1,8 = 17,28

b, 17,28 + 3,2 x 1,6 x 2

= 17,28 + 5,12 x 2

= 17,28 + 10,24 = 27,52

 (3,2 + 1,6 ) x 2 x 1,8

= 4.8 *2*16

=17.28

a) 3,37 + X = 76,8 

X = 76,8 - 3,37

X = 73.43

b) x - 34,8 = 4,56 + 8,44 

 x - 34,8 = 13

x = 13 + 34,8 

x = 47.8

c) 8,2 x X = 28,7 

x = 28,7 : 8,2

x = 3.5

d) 45 ,56 - x = 23 ,8 

x  = 45,56 - 23,8

x = 21.76

đ) 25 : x = 1,6 

x = 25 : 1,6

x = 15.625

e) x : 3,2 =8,25

x = 8,25 x 3,2

x = 26.4

\(a,x=76,8-3,37\)

\(x=73,43\)

\(b,x-34,8=13\)

\(x=13+34,8\)

\(x=47,8\)

\(c,x=28,7:8,2\)

\(x=3,5\)

\(d,x=45,56-23,8\)

\(x=21,76\)

\(đ,x=25:1,6\)

\(x=15,625\)

\(e,x=8,25\times3,2\)

\(x=26,4\)

a) 3,37 + X = 76,8 

X = 76,8 - 3,37

X = 73.43

b) x - 34,8 = 4,56 + 8,44 

 x - 34,8 = 13

x = 13 + 34,8 

x = 47.8

c) 8,2 x X = 28,7 

a)64x25+35x25+25=25x(64+35)+25=25x99+25=2475+25=2500

mình trả lời ý a

64 x 25 +35 x 25 +25 x 1

= 25 x ( 64 + 35 + 1 )
= 25 x 100

= 2500

Tính nhanh:

a) 64 x 25 + 35 x 25 + 25 

= 64 x 25 + 35 x 25 + 25 x 1

= 25 x ( 64 + 35 + 1 )

= 25 x 100

= 2500

  b) 58 x 42 + 32 x 8 + 5 x 16

= 

a) 2 x 12 x 43 + 3 x 32 x 8 + 25 x 6 x4

=(2 x12) x43+(3 x8) x32+(6 x4) x25

=24 x43+24 x32+ 24 x25

=24 x(43+32+25)

=24 x100

=2400

b) 78 x 31 + 78 x 24 + 17 x 78 + 28 x 78

=78x(31+24+17+28)

=78x100

=7800

thanks bạn nha

78 x 31 + 78 x 24 + 17 x 78 +28 x 78 = 78 x ( 31 + 24 + 17 +28 ) =78 x 100 =7800 mình chỉ biết làm phần B thôi thông cảm cho mình nha

1: \(=75\left(27+25-2\right)=75\cdot50=3750\)

2: \(=15\left(23+37\right)+55=15\cdot60+55=955\)

3: \(=36\cdot14+36\cdot17+36\cdot69\)

\(=36\cdot100=3600\)

4: \(=200\cdot\left(32+68\right)=200\cdot100=20000\)

Trả lời

\(0,8\cdot70+3,2\cdot6+1,6\cdot3\)

\(=56+19,2+4,8\)

\(=56+\left(19,2+4,8\right)\)

\(=56+24\)

\(=80\)

0,8 x 70 + 3,2 x 6 + 1,6 x 3

= 0,8 x 70 + 0,8 x 4 x 6 + 0,8 x 2 x 3

= 0,8 x (70 + 4 x 6 + 2 x 3)

= 0,8 x (70 + 24 + 6)

= 0,8 x (94 + 6)

= 0,8 x 100

= 80

0,8 x 70 + 3,2 x 6 + 1,6 x 3

= 56       + 19,2     + 4,8

=56        + 24

= 80

a, (-4) . (+125) . (-25) . 6 . (-8)

  =[ (-4) . (-25) ] . [ (+125) . (-8) ] . 6

  =    100          .        (-1000)      . 6

  =              -100 000                  . 6

  =                     -600 000

b,  122 . (-12345) + 12345 . (-78)

   = 12345 . [ (-122) + (-78) ]

   = 12345 .        (-200)

   =      -2 469 000

c,  36 . (-9) + 9 . (-64)

  =  9 .  [ (-36) + (-64) ]

  =  9 .         (-100)

  =       -900