… = 25 x (36 : 9) = 25 x 4 = 100

(25 x 36) : 9 = 25 x (36 : 9) = 25 x 4 = 100

phòng có số bộn bàn ghế là : 240 : 15 = 16 [bộ]                                                                                                                                                                                             đ/s:16 bộ

\(\dfrac{1}{10}+\dfrac{4}{20}+\dfrac{9}{30}+\dfrac{16}{40}+\dfrac{25}{50}+\dfrac{36}{60}+\dfrac{49}{70}+\dfrac{64}{80}+\dfrac{81}{90}\)
\(=\dfrac{1}{10}+\dfrac{1}{5}+\dfrac{3}{10}+\dfrac{2}{5}+\dfrac{1}{2}+\dfrac{3}{5}+\dfrac{7}{10}+\dfrac{4}{5}+\dfrac{9}{10}\)
\(=\left(\dfrac{1}{10}+\dfrac{3}{10}+\dfrac{7}{10}+\dfrac{9}{10}\right)+\left(\dfrac{1}{5}+\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{4}{5}\right)+\dfrac{1}{2}\)
\(=2+2+\dfrac{1}{2}\)
\(=4+\dfrac{1}{2}\)
\(=\dfrac{8}{2}+\dfrac{1}{2}=\dfrac{9}{2}\)

\(A=\dfrac{404\times25+75\times404}{2038-9-9}\)

\(=\dfrac{404\times\left(25+75\right)}{2029-9}\)

\(=\dfrac{404\times100}{2020}\)

\(=\dfrac{40400}{2020}\)

\(=20\)

#\(Toru\)

   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

TL: 

8/15 x 5/6 = 40/90 = 4/9 

41/20 x 3/4 = 123/80 

(11/23 + 9/23) + (18/23 + 2/23) = 20/23 + 20/23 = 40/43 

HT

\(\left(\frac{2}{3}\times\frac{4}{5}\right)\times\frac{5}{6}\) = \(\frac{2}{3}\times\frac{4}{5}\times\frac{5}{6}\)=\(\frac{2\times4\times5}{3\times5\times6}\)=\(\frac{2\times4\times5}{3\times5\times2\times3}\)=\(\frac{4}{9}\)

\(\frac{11}{23}+\frac{2}{23}+\frac{9}{23}+\frac{18}{23}\)=\(\frac{\left(11+9\right)+\left(18+2\right)}{23}\)=\(\frac{20+20}{23}\)=\(\frac{40}{23}\)

\(\frac{27}{12}+\frac{17}{6}-\frac{25}{36}-\frac{15}{6}\)=\(\left(\frac{27}{12}-\frac{25}{36}\right)+\left(\frac{17}{6}-\frac{15}{6}\right)\)=\(\frac{14}{9}+\frac{2}{6}\)=\(\frac{17}{9}\)

/HT\

Nhập các bạn toàn bắt tớ làm à ngu gò mà làm

698 x 36 - 698 x 25 - 698

= 698 x 36 - 698 x 25 - 698 x 1

= 698 x (36 - 25 - 1)

= 698 x 10

= 6980

----

Hok tốt nha bn!

=6980 nha bạn

chúc bạn hok tốt nha

698 x 36 - 698 x 25 - 698

= 698 x 36 - 698 x 25 - 698 x 1

= 698 x (36 - 25 - 1)

= 698 x 10

= 6980

a.245 x ( 327-18-9) = 245 x 300 = 73500

b. (462 - 62) x 4 = 1600

c. 900 : 9 = 100

d. (12+20) : 4 = 8

462 x 4 - 62 x 4

= 4 x ( 462 - 62 )

= 4 x 400

= 1600

35 : 7 - 21 :7

= ( 35 - 21 ) : 7

=  14 : 7

= 2

( 25 x 36 ) : 9

= 25 x ( 36 : 9 )

= 25 x 4

= 100

245 x 327 - 245 x 18 - 9 x 245

= 245 x ( 327 - 18 - 9 )

= 245 x 218

= 53410

12 : 4 + 20 : 4

= ( 12 + 20 ) : 4

= 24 : 4

Chúc em học tốt \ ( ^ o ^ ) / tick cho nha

245x327-245x18-9x245                           462 x 4 - 62 x 4   

=245x(327-18-9)                                       = ( 462 - 62) x 4

=245x300                                                  = 400 x 4

=73500                                                      = 1600

   35 : 7 - 21 : 7                                             ( 25 x 36 ) : 9    

= ( 35 - 21) : 7                                           = 900 : 9

= 14 : 7                                                     = 100

= 2

12 : 4 + 20 : 4

= ( 12 + 20 ) : 4

= 32 : 4

= 8

a. 36 × 25 × 4 = 36 × 100 = 3600

b. 18 × 24 : 9 = ( 18 : 9) × 24 = 2 × 24 = 48

c. 215 × 86 + 215 × 14 = 215 × ( 86 + 14) = 215 × 100 = 21500