a) 19,17x25x4=19,17(25x4)=19,17x100=1917

b)1,79x(8x125)=1,79x1000=1790

chúc bạn học tốt

Lời giải:

$x\times 25+x:0,25=2900$

$x\times 25+x\times 4=2900$

$x\times (25+4)=2900$

$x\times 29=2900$

$x=2900:29=100$

\(2900\times94+2900+2900\times5\)

\(=2900\times\left(94+1+5\right)\)

\(=2900\times100\)

\(=290000\)

a) 2900 x 94 + 2900 + 2900 x 5

  =2900 x (94+1+5)

  =2900 x 100

  =290000

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cảm ơn các bạn nhé mình xong r

24.25+102.94-94-94

=4.25.6+94.(102-1-1)

=100.6+94.100

=100.(6+94)

=100.100

=10000

HT

dấu nhân là chữ x thường nha

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

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

1. A) 225886 + 779 × 8

= 225886 + 6232

= 232118

B) 125 × 5 × 20 × 8

= (125 × 8) × (5 × 20)

= 1000 × 100

= 100000

C) 47286 : 2 + 14765

= 23643 + 14765

= 38408

D) 91428 - 23560 : 5

= 91428 - 4712

= 86716

3. A) 36 × 532 + 63 × 532 + 532

= 532 × (36 + 63 + 1)

= 532 × 100

= 53200

B) 679 × 123 + 679 - 679 × 24

= 679 × (123 + 1 - 24)

= 679 × 100

= 67900

C) 245 × 327 - 245 × 18 - 9 × 245

= 246 × (327 - 18 - 9)

= 245 × 300

= 73500

2. A) 6 × (x + 9845) = 29042

x + 9845 = 29042 : 6

x + 9845 = 14521/3

x = 14521/3 - 9845

x = -15014/3 < 0

Em xem lại đề vì lớp 4 chưa học số âm

B) (x : 3) × 8 = 8 × 3198

x : 3 = 3198

x = 3198 × 3

x = 9594

   35  x 20 x 5           8 x 9 x 125         25 x 7 x 4    72:(8x3)

= 35 x ( 20  x5 )      = ( 8x125) x 9    = (25x4)x7    = 72: 24

= 35 x 100              = 1 000 x 9       = 100x7        = 3

= 3 500                  = 9  000            =700

(36x7):4

=36: 4 x 7 

= 9 x7

= 63 

35 x 20 x 5 = 35\(\times\)(20 \(\times\)5)= 35 \(\times\)100=3500

8 \(\times\)9 \(\times\) 125 =(8\(\times\) 125)\(\times\)9=1000\(\times\)9=9000

25 \(\times\)7\(\times\)4=(25 \(\times\)4)\(\times\)7=100\(\times\)7=700

72 : (8\(\times\)3)=72 : 8 x 3 =(72:8) x 3=9 x   3=27

(36 x 7) : 4 =36 x 7 : 4 =7 x (36 :4)=7 x 9=63

b. 2 x 8 x 50 x 25 x 125 = (2 × 50) × (8 × 125) × 25

= 100 × 1000 × 25

= 100000 × 25

= 2500000

= ( 2x50) x ( 8x125) x 25

= 100 x 1000 x 25

100000 x 25

= 2500000

b. 2 x 8 x 50 x 25 x 125 = (2 × 50) × (8 × 125) × 25

= 100 × 1000 × 25

= 100000 × 25

= 2500000