a, 40 b, 0 c, 0  d, 120

\(\frac{8}{11}\cdot\frac{14}{13}+\frac{9}{23}\div\frac{11}{8}-\frac{8}{11}\)

\(=\frac{8}{11}\cdot\frac{14}{13}+\frac{9}{23}\cdot\frac{8}{11}-\frac{8}{11}\)

\(=\frac{8}{11}\cdot\left(\frac{14}{13}+\frac{9}{23}-1\right)\)

\(=\frac{8}{11}\cdot\frac{140}{299}=\frac{1120}{3289}\)

doi ra so nho duoc ko ban

\(=\dfrac{7}{23}\left(\dfrac{8}{11}-\dfrac{3}{11}\right)-\dfrac{16}{23}=\dfrac{7}{23}\cdot\dfrac{5}{11}-\dfrac{16}{23}=-\dfrac{141}{253}\)

`a)3/5+(-4/9)`

`=3/5-4/9`

`=27/45-20/45`

`=7/45`

`b)3/5+2/5 . 15/8`

`=3/5 + 30/40`

`=3/5+3/4`

`=12/20+15/20`

`=27/20`

`c)7/2 . 8/13 + 8/13 . (-5/2)`

`=8/13 . (7/2 +(-5)/2)`

`=8/13 . 1`

`=8/13`

`d)-5/17 . (-9/23)+9/23 . (-22/17) + 11 9/23`

`=-5/17 . (-9/23) + 9/23 . (-1) . 22/17 + 11 + 9/23`

`=-5/17 . (-9/23) + (-9/23) . 22/17+11+9/23`

`= -9/23 ( -5/17 + 22/17)+11+9/23`

`= - 9/23 . 1+11+9/23`

`=-9/23+11+9/23`

`=(-9/23+9/23)+11`

`=0+11`

`=11`

a: =27/45-20/45=7/45

b: =3/5+30/40

=3/5+3/4

=12/20+15/20

=27/20

c: =8/13(7/2-5/2+1)=8/13*2=16/13

d: =9/23*5/17-9/23*22/17+11+9/23

=-9/23+11+9/23

=11

56666666

1135/23-167/32+330/23

=(1135/23-330/23)+167/32

=805/23+167/32

=35+167/32

=1120/32+167/32

=1287/32

\(A=\frac{3}{2}\times5+\frac{3}{5}\times8+\frac{3}{8}\times11+.....+\frac{3}{20}\times23+\frac{3}{23}\times26\)

\(A=\frac{3}{2}\times\frac{5}{1}+\frac{3}{5}\times\frac{8}{1}+\frac{3}{8}\times\frac{11}{1}+.....+\frac{3}{20}\times\frac{23}{1}+\frac{3}{23}\times\frac{26}{1}\)

\(A=\left(\frac{3}{2}\times\frac{5}{1}+\frac{3}{23}\times\frac{26}{1}\right)+.....+\left(\frac{3}{11}\times\frac{14}{1}+\frac{3}{14}\times\frac{17}{1}\right)\)CÓ 8 CẶP

\(A=\left(\frac{15}{2}+\frac{68}{23}\right)+.....+\left(\frac{42}{11}+\frac{51}{14}\right)\)

\(A=\left(\frac{15}{2}+\frac{68}{23}\right)+.....+\left(\frac{42}{11}+\frac{51}{14}\right)\)

CÒN LẠI TỰ GIẢI NHA

tinh tong sau bang cach hop li A Ban

9/14 .<.. 11/14           4/25 .<.. 4/23          5/6 ..<. 7/8         1 ..>. 14/15

8/9 ..=. 24/27             20/19 ..>. 20/27        8/7 .>.. 9/8        1 .<..15/14

\(\dfrac{9}{14}< \dfrac{11}{14};\dfrac{8}{9}=\dfrac{24}{27}\)

\(\dfrac{4}{25}< \dfrac{4}{23};\dfrac{20}{19}>\dfrac{20}{27}\)

\(\dfrac{5}{6}< \dfrac{7}{8};\dfrac{8}{7}>\dfrac{9}{8}\)

\(1>\dfrac{14}{15};1< \dfrac{15}{14}\)

9/14 .<.. 11/14           4/25 .<.. 4/23          5/6 ..<. 7/8         1 ..>. 14/15

8/9 ..=. 24/27             20/19 ..>. 20/27        8/7 .>.. 9/8        1 .<..15/14

a)\(\left(\frac{25}{49}+\frac{17}{39}+\frac{22}{39}\times\frac{25}{49}\right)\times\frac{41}{25}\)

\(=\left(\frac{25}{49}+\left(\frac{17}{39}+\frac{22}{39}\right)\times\frac{25}{49}\right)\times\frac{41}{25}\)

\(=\left(\frac{25}{49}+\frac{39}{39}\times\frac{25}{49}\right)\times\frac{41}{25}\)

\(=\left(\frac{25}{49}+1\times\frac{25}{49}\right)\times\frac{41}{25}\)

\(=\left(\frac{25}{49}+\frac{25}{49}\right)\times\frac{41}{25}\)

\(=\frac{50}{49}\times\frac{41}{25}\)

\(=\frac{2050}{1225}\)