a)

164,7 x 0,91 - 64,7 x 0,91

= 0,91 x ( 164,7 - 64,7 )

=0,91 x 100

=91

b)

2,5 x 12,5 x 8 x 0,4

=(2,5 x 0,4) x ( 12,5 x 8)

=1 x 100

=100

a) 164,7 x 0,91 - 64,7 x 0,91

= 0,91 x ( 164,7 - 64,7 )

= 0,91 x 100

= 91

b ) 2,5 x 12,5 x 8 x 0,4

= ( 2,5 x 0,4 ) x ( 12,5 x 8 )

= 1 x 100

= 100

a)91

b)100

\(\dfrac{1}{3}+\dfrac{6}{5}-\dfrac{1}{5}+\dfrac{2}{3}=2\)

1/3+6/5−1/5+2/3=2

1212/1515 = 1212 :1515 

= 12 x 101 : 15 x 101 

= 12/15

dinh hoang vu

\(\frac{1212}{1515}=\frac{1212\div101}{1515\div101}\)

\(=\frac{12}{15}=\frac{4}{5}\)

\(\frac{1212}{1515}=\frac{2^2.3.101}{3.5.101}=\frac{2^2}{5}=\frac{4}{5}\)

  25x20x125x8-8x20x5x125

=(25x8)x(20x125)-(20x5)x(8x125)

=200x2500-100x1000

=500000-100000=400000

mk tính giống bạn kia

giai giup minh nha

476x72+476x28

=476x(72+28)

=476x100

=47 600

476x72+476x28

=476x(72+28)

=476x100

=47 600

54x342-44x342

=342x(54-44)

=342x10

=3 420

54x342-44x342

=342x(54-44)

=342x10

=3 420

54x342-44x342

=342x(54-44)

=342x10

=3 420

 48,25 + 12,72 + 51,75 + 87,28
  = (48,25 + 51,75) + (12,72 + 87,28)
  = 100 + 100
  = 200

 a) 48,25+12,72+51,75+87,28

= (48,25+51,75) + (12,72+ 87,28)

=         100         +         100

=                       200

200

( 742+258) + 316=1000 + 356=1356

742+316+258 = 1316