a) \(125\times25\times8\times4\)
\(\Rightarrow\left(125\times8\right)\times\left(25\times4\right)\)
\(\Rightarrow1000\times100\)
\(\Rightarrow100000\)

\(\text{a. 125 x 25 x 8 x 4 }\\ =125.8.25.4\\ =1000.100=100000\)

\(\text{ b. 25 x 32 x 125 x 15}\\ =25.15.32.125\\ =375.4000=1500000\)

b.25 x 32 x 125 x 15=25 x 4 x 8 x 125 x 15

                                =(25 x 4) x (125 x 8) x15

                                =100 x 1000 x 15 = 1500000

101 \(\times\) 9,4 - 9,4 + 25 \(\times\) \(\dfrac{2,4}{250\%}\) \(\times\) 125% \(\times\) 32

= 9,4 \(\times\) ( 101 - 1) + 25 \(\times\) \(\dfrac{2,4}{2,5}\) \(\times\) 125% \(\times\) 8 \(\times\) 4

= 9,4 \(\times\)100 + 25 \(\times\) \(\dfrac{24}{25}\) \(\times\) 10 \(\times\) 4

= 94 \(\times\)10 + 24 \(\times\) 4 \(\times\) 10

= 10 \(\times\) ( 94 + 96)

= 10 \(\times\) 190

= 1900 

\(25\times32\times125\times15\\=(25\times4)\times(8\times125)\times15\\=100\times1000\times15\\=100000\times15\\=1500000\)

25 x 32 x 125 x 15 

=(125 x 32 ) x (25 x 15 )

= 4000 x 375

=1 500 000

\(25\times32\times125\times15\)

\(=25\times4\times8\times125\times15\)

\(=\left(25\times4\right)\times\left(8\times125\right)\times15\)

\(=100\times1000\times15\)

\(=\left(1000\times15\right)\times100\)

\(=15000\times100=1500000\)

\(\dfrac{31}{48}\times\dfrac{32}{93}\)

\(=\dfrac{31\times32}{48\times93}\)

\(=\dfrac{1\times2}{3\times3}\)

\(=\dfrac{2}{9}\)

============

\(\dfrac{77}{80}\times\dfrac{48}{49}\)

\(=\dfrac{77\times48}{80\times49}\)

\(=\dfrac{11\times3}{5\times7}\)

\(=\dfrac{33}{35}\)

=============

\(\dfrac{154}{125}\times\dfrac{25}{44}\)

\(=\dfrac{154}{125}\times\dfrac{25}{44}\)

\(=\dfrac{7\times1}{5\times2}\)

\(=\dfrac{7}{10}\)

31x72 - 31x70 - 31 x 2 - 31

=31x(72 -70 -2 -1)

=31 x (-1)

= -31

những câu sau thì lam tương tự nha bạn ^_^

giải giùm mình nhen mn. lu

\(a,\left(25\times32\right):8=25\times\left(32:8\right)=25\times4=100\\ b,\left(56\times125\right):7=\left(56:7\right)\times125=8\times125=1000\)

=100

=1000

dễ thương quá minion 

d, X/8*32+X/3*18-X/5*10=120

   X*32/8+X*18/3-X*10/5=120

  32X/8+18X/3-10X/5=120

  4X+6X-2X=120

  8X=120

 X=120/8

X=15

a, ( 25 * 12 - X - 25 ) : 25 = 4

( 25 * 12 - x - 25 )           = 4 * 25 

( 25 * 12 - x - 25 )           = 100

300 - x - 25                    = 100

300 - x                           = 100 + 25

300 - x                           = 125

x                                   = 300 - 125

x                                   = 175

a)=210

b)=8100

c)=3900

d)=49000

e)=100000

a ) 2 x 3 x 5 x 7

= ( 2 x 5 ) x 3 x 7

= 10 x 21

= 210

b ) 50 x 9 x 9 x 2

= ( 50 x 2 ) x 9 x 9

= 100 x 81

= 8100

c ) 13 x 25 x 3 x 4

= ( 25 x 4 ) x 13 x 3

= 100 x 39

= 3900

d ) 7 x 125 x 7 x 8

= ( 125 x 8 ) x 7 x 7

= 1000 x 49

= 49000

e ) 25 x 32 x 125

= 800 x 125

= 100000

a] 210

a)9200

9200

6400

b)50

50

19,5

c)128

128

60

a)    92 : 0,01 = 9200          92 x 100 = 9200        64 : 0,01= 6400

b)    25 : 0,5 = 50           25 x 2 = 50           39 : 0,5 = 78
c)    32 : 0,25 = 128         32 x 4 = 128          15 : 0,25 = 60

a)92 : 0,01 = 9200      92 x 100 = 9200          64 : 0,01 = 6400
b)25 : 0,5 = 50            25 x 2 = 50                  39 : 0,5 = 78
c)32 : 0,25 = 128        32 x 4 = 128                 15 x 0,25 = 60