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\

=11/6*(15/23-7/23)
=11/6*8/23
=44/69
chúc bn hk tốt

\(\frac{11}{6}\times\frac{15}{23}-\frac{11}{6}\times\frac{7}{23}\)=  \(\frac{11}{6}\times\left(\frac{15}{23}-\frac{7}{23}\right)\)

                                                       =\(\frac{11}{6}\times\frac{8}{23}\)

                                                       =  \(\frac{44}{69}\)

a)Vì có nhiều số 52 nên .52x(3+7)=52x10=520

b)Vì có nhiều số 23 nên.23x(2+6+2)=23x10=230

c)Vì  số 64 phép cuối ko có số nhân nên ta coi số đó là 1 nên. 64x7+64x2+64x1=64x(7+2+1)=64x10=640

d)Vì phép tính ở giữa có 2 số 48 cộng nên ta coi đó là 1 nên.48x(3+6+1)=48x10=480

nhé

a) 52 x 7 + 52 x 3 

= 52 x ( 7 + 3 ) 

= 52 x 10 

= 520

b) 23 x 2 + 6 x 23 + 23 x 2 

= 23 x ( 2 + 6 + 2 )

= 23 x 10

= 230

c) 64 x 7 + 64 x 2 + 64 

= 64 x 7 + 64 x 2 + 64 x 1 

= 64 x ( 7 + 2 + 1 ) 

= 64 x 10 

= 640

d) 48 x 3 + 48 + 48 x 6 

 = 48 x 3 + 48 x 1 + 48 x 6 

 = 48 x ( 3 + 1 + 6 )

= 48 x 10

= 480

\(a.=\left(\dfrac{4}{5}.\dfrac{5}{6}\right).\dfrac{2}{3}=\dfrac{4}{6}.\dfrac{2}{3}=\dfrac{4}{9}\)

\(b.\dfrac{4}{5}.\dfrac{3}{4}+\dfrac{5}{4}.\dfrac{3}{4}=\dfrac{3}{5}+\dfrac{15}{16}=\dfrac{123}{80}\)

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

\(d.\left(\dfrac{27}{12}-\dfrac{25}{36}\right)+\left(\dfrac{17}{6}-\dfrac{15}{6}\right)=\dfrac{14}{9}+\dfrac{1}{3}=\dfrac{17}{9}\)

dấu chấm là gì vậy

a, = \(\frac{11}{21}\)x \(\left(\frac{7}{4}+\frac{5}{4}\right)\)

   = \(\frac{11}{21}\)x 3

  = \(\frac{33}{21}\)

b) = \(\left(\frac{23}{14}-\frac{9}{14}\right)\)x \(\frac{6}{13}\)

    = 1 x \(\frac{6}{13}\)

    = \(\frac{6}{13}\)

dhfwjrfsdkjbskndksjldkfnvkrfghnkjfhwkjfhwk fjghalkuerfgebkrfhjedhksejhlkjrhwejhrbhejrkfljrhebrhfejljrheklruhlwkuiytowhrjeklrjhgs.kjrw3ilvhwiort4jhkw3hr4kjthekjhrtlwejhtlrbvkwytgvkuwehltvgikehrltuiwyhlbiuvyhlitbhlwwncttolwy4twkthnwcjrhtw.ktvjhb q.tilhywcb.wcb.rvyhf.gvniyqt8ot8ot8ot8oy;weniweniweniweniweniweniweniweniweniweniweniwenifh.asklbghsbjkvhagkle/vm sgjfvbklhdfklagh/vekjjjr;klgbjal/bgujrvkll/anwko;tgj/vbal/skjgbkrvjgka.

a,17/23 + (1 - 17/23)

= 17/23 + 6/23

= 23/23 = 1

b,17/12 + 9/7 - (2/7 + 5 /12)

= (17/12 - 5/12) + (9/7 + 2/7)

= 1+1 = 2

c, 7/13 - ( 4/7 -6/13 )

= 7/13 - 4/7+ 6/13

= (7/13 + 6/13) -4/7

= 13/13 -4/7

= 1 -4/7 = 3/7

hok tốt✍️ ✍️

a)   17/23+(1-17/23)

=17/23+1-17/23

=1

b)17/12+9/7-(2/7+5/12)

=17/12+9/7-2/7-5/12

=1+1

=2

c)

7/13-(4/7-6/13)

=7/13-4/7+6/13

=1-4/7

=3/7

Lấy các số cùng mẫu gộp lại tính trước 

a) 17/23 + (1 - 17/23)

= 17/23 + 1 - 17/23

= (17/23 - 17/23)  + 1

= 0 + 1 = 1

b) 17/12 + 9/7 - (2/7 + 5/12)

= 17/12 + 9/7 - 2/7 - 5/12

= (17/12  - 5/12) + (9/7 - 2/7)

= 1 + 1 = 2

c) 7/13 - (4/7 - 6/13)

= 7/13 - 4/7 + 6/13

= (6/13 + 6/12) - 4/7

= 1 - 4/7 = 3/7

d) 7/18 + 3/16 + 11/18 + 13/16

= (7/18 + 11/18) + (3/16 + 13/16)

= 1 + 1 = 1

d) sửa 7/18 + 3/16 + 11/18 + 13/16

= (7/18 + 11/18) + (3/16 + 13/16)

= 1 + 1

= 2

\(\dfrac{11}{34}+\dfrac{5}{23}+\dfrac{23}{34}+\dfrac{18}{23}\)
\(=\left(\dfrac{11}{34}+\dfrac{23}{34}\right)+\left(\dfrac{5}{23}+\dfrac{18}{23}\right)\)
\(=1+1\)
\(=2\)
#DatNe

=2