19/11 + [ 8/13 + 3,11 ]

= [ 19/11 + 3/11 ] + 8/13

=   22/11 + 8/13

= 2 + 8/13

= 34/13

19/11 + ( 8/13 + 3/11 ) = 19/11 + 8/13 + 3/11 = ( 19/11 + 3/11 ) + 8/13 = 2 + 8/13 = 26/13 + 8/13 = 34/13

k mk nha mk k lai

\(2\frac{8}{13}\)

\(\frac{4}{15}+\frac{8}{13}+\frac{11}{15}+\frac{5}{13}\)

\(=\left(\frac{4}{15}+\frac{11}{15}\right)+\left(\frac{8}{13}+\frac{5}{13}\right)\)

\(=\frac{15}{15}+\frac{13}{13}\)

\(=1+1\)

\(=2\)

Chúc bạn học tốt nha !!! 

\(\frac{4}{15}+\frac{8}{13}+\frac{11}{15}+\frac{5}{13}\)

\(=\left(\frac{4}{15}+\frac{11}{15}\right)+\left(\frac{8}{13}+\frac{5}{13}\right)\)

\(=1+1\)

\(=2\)

=(4/15+11/5)+(8/13+5/13)

=37/15+1=52/15

k mink nha

2x25x50xx8=(25x8)x(50x2)=200x100=20000

12x11+21x11+11x33=11x(12+21+33)=11x66=726

2*25*50*8

=(2*50)*(25*8)

=100*200=20000

12*11+21*11+11*33

=11*(12+21+33)

=11*66=676

2 x 25 x 50 x 8  = (8 x 25) x (50 x 2) = 200 x 100 = 20000

b) 12 x 11 + 21 x 11 + 11 x 13 = 11 x (12 + 21 + 33) 

= 11 x 66 = 726

20,11x96+20,11:0,25

=20,11x96+20,11x4

=20,11x100

=201,1

20, 11×96+20, 11:0, 25

= 20,11 x 96 + 20,11 x 4

= 20,11 x ( 96 + 4 )

= 20,11 x 100

= 2011

   20,11 x 96 + 20,11 : 0,25

= 20,11 x 96 + 20,11 x 4

= 20,11 x (96+4)

= 20,11 x 100

= 2011

Giải thích hơi dài, tớ chỉ ghi đ/s thôi.

Đ/s: 1.

20/11*33/23*69/180=20*33*69/11*23*180=9/9=1

( 23 + 47) + (11 + 49) = 50 + 50 = 100

(4. 25) . (7 . 11) = 100 . 77 = 7700

23 + 47 + 11 + 49

=( 23 + 47 ) + (11+49)

= 70+60

=130

4.7.11.25

= (4.25) . (7.11)

=100 . 77

= 7700

k mình nha bn

\(23+47+11+49\)

\(=\left(23+47\right)+\left(11+49\right)\)

\(=70+60\)

\(=130\)

\(4.7.11.25\)

\(=\left(4.25\right).\left(7.11\right)\)

\(=100.77\)

\(=7700\)

23+47+11+49

=(23+47)+(11+49)

=    70    +   60

=          130

4.7.11.25

=(4.25).(7.11)

=  100 .  77

=     7700

5.9.3.2

=(5.2).(3.9)

=   10.  27

=     270

23+47+11+49 = 70 + 60 = 130

4.7.11.25 = 4 . 25 . 7 . 11 = 100 x 77 = 7700

5.9.3.2 = 5 x 2 x 3 x 2 = 10 x 6 = 60 

\(23+47+11+49\)

\(=\left(23+47\right)+\left(11+49\right)\)

\(=70+60\)

\(=130\)

\(4x7x11x25\)

\(=\left(4x25\right)x\left(7x11\right)\)

\(=100x77\)

\(=7700\)

\(5x9x3x2\)

\(=\left(5x2\right)x\left(9x3\right)\)

\(=10x27\)

\(=270\)

K mình nha mình nhanh nhất đó!

(7/11+4/11)+3/4+1

=1+3/4+1

=11/4

\(\frac{7}{11}+\frac{3}{4}+\frac{4}{11}+\frac{1}{4}=\left(\frac{7}{11}+\frac{4}{11}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)=1+1=2\)

\(\frac{7}{11}\)+ \(\frac{3}{4}\) + \(\frac{4}{11}\) + \(\frac{1}{4}\)

= \(\left(\frac{7}{11}+\frac{4}{11}\right)\)+ \(\left(\frac{3}{4}+\frac{1}{4}\right)\)

= 1 + 1

= 2

\(\frac{72}{99}\)- \(\frac{28}{99}\) - \(\frac{14}{99}\)

= \(\frac{72}{99}\) - \(\left(\frac{28}{99}+\frac{14}{99}\right)\)

= \(\frac{72}{99}\) - \(\frac{42}{99}\)

= \(\frac{30}{99}\)

\(\frac{7}{11}+\frac{3}{4}+\frac{4}{11}+\frac{1}{4}\)

\(=\left(\frac{7}{11}+\frac{4}{11}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)\)

\(=1+1=2\)

\(\frac{72}{99}-\frac{28}{99}-\frac{14}{99}\)

\(=\frac{72-24-14}{99}\)

\(=\frac{34}{99}\)