a: =(8/27+19/27)+(4/15+11/15)=1+1=2

b: =(12/13+8/13+6/13)+(2/7+5/7)=2+1=3

\(=\frac{17}{8}:\left(-\frac{17}{8}\right)=-1\)

\(\dfrac{5}{27}-\dfrac{2}{-27}=\dfrac{5}{27}+\dfrac{2}{27}=\dfrac{7}{27}\)

\(\dfrac{7}{-25}+\dfrac{-8}{25}=\dfrac{\left(-7\right)+\left(-8\right)}{25}=\dfrac{-15}{25}=\dfrac{-3}{5}\)

\(\dfrac{23}{-11}-\dfrac{-3}{-11}=\dfrac{\left(-23\right)-3}{11}=\dfrac{-26}{11}\)

a 475 - ( 75 + 36 ) = 475 - 75 - 36

= 400 - 36

= 364

b 821 - 73 - 27 - 21

= ( 821 - 21 ) - ( 73 + 27 )

= 800 - 100

= 700

a ) 475 - ( 75 + 36 )

= 475 - ( 75 + 35 ) - 1

= ( 475 - 1 ) - 100

= 474 - 100 = 374

b ) 821 - 73 - 27 - 21

= ( 821 - 21 ) - ( 73 + 27 )

= 800 - 100

= 700

c ) \(\frac{37}{25}\div\frac{5}{4}\div\frac{74}{25}\)

\(=\frac{37\cdot2\cdot2\cdot25}{25\cdot5\cdot37\cdot2}\)

\(=\frac{2}{5}\)

c 37/25:5/4:74/25

=37/25 x 4/5 x 25/74

=37 x 4 x 25/5 x 25 x 74

=2/5.

d 6/11 : 4/3  + 5/11 

=(6/11:5/11):(4/3:4/3)

=6/5:1

=6/5

a) Ta có: \(\left(\dfrac{-1}{2}\right)^2\cdot\dfrac{7}{4}:\left(\dfrac{5}{8}-1\dfrac{3}{16}\right)\)

\(=\dfrac{1}{4}\cdot\dfrac{7}{4}:\left(\dfrac{5}{8}-\dfrac{19}{16}\right)\)

\(=\dfrac{1}{4}\cdot\dfrac{7}{4}:\dfrac{-9}{16}\)

\(=\dfrac{1}{4}\cdot\dfrac{7}{4}\cdot\dfrac{-16}{9}\)

\(=\dfrac{-112}{144}=\dfrac{-7}{9}\)

b) Ta có: \(17\dfrac{6}{11}\cdot\dfrac{4}{27}-8\dfrac{6}{11}:\dfrac{27}{4}+350\%\)

\(=17\dfrac{6}{11}\cdot\dfrac{4}{27}-8\dfrac{6}{11}\cdot\dfrac{4}{27}+350\%\)

\(=\dfrac{4}{27}\left(17+\dfrac{6}{11}-8-\dfrac{6}{11}\right)+\dfrac{7}{2}\)

\(=\dfrac{4}{27}\cdot9+\dfrac{7}{2}\)

\(=\dfrac{4}{3}+\dfrac{7}{2}=\dfrac{8}{6}+\dfrac{21}{6}=\dfrac{29}{6}\)

10) 37.(27+25)-27.(37+25)=37.27+37.25-27.37-27.25

=37.25-27.25=25(37-27)=25.10=250

11)3.(-5+3)+7(2+5)=3.(-2)+7.7=-6+49=43

12)-3.(2-7)-6(8-5)=-3.(-5)-6.3=15-18=-3

a) 37. (27 +25)-27.(37+25)

= 37.52-27.62

= (37-27).(52-62)

= 10.-10

=-100

b) 3.(-5+3)+7.(2-5)

= 3.-2+7.-3

= (3+7).[(-2)-(-3)]

=10.1

=10

c) -3.(2-7)-6.(8-5)

= -3.-5-6.3

= (-3-6).(-5-3)

=(-9).(-8)

=72

tick nha

8/27+4/5+19/27+11/15=(8/27+19/27) + (4/5+11/15)

                                    = 1+ (12/15+11/15)

                                    = 1+ 1/8/15=2/8/15

12/13+2/7+8/13+6/13+5/7=(12/13+8/13+6/13) + (2/7+5/7)

                                         = 2+ 1

                                         =3

Ý a có thể bạn chép nhầm 4/5 rồi

= 2 + 1=3 nhé bạn

\(\left(-\frac{1}{2}\right)^2\cdot2\cdot\frac{7}{4}\div\left(\frac{5}{8}-1\frac{3}{16}\right)\)

\(=\frac{1}{4}\cdot2\cdot\frac{7}{4}\div\left(\frac{10}{16}-\frac{19}{16}\right)\)

\(=\frac{7}{8}\div\left(-\frac{9}{10}\right)\)

\(=\frac{7}{8}\cdot\left(-\frac{10}{9}\right)\)

\(=-\frac{35}{36}\)

-1/2^2.7/4:(5/8-1 3/16)=1/4.7/4:(5/8-19/16)=1/4.7/4:(10/16-19/16)=1/4.7/4:-9/16=1/4.7/4.-16/9=1/4.-28/9=-7/9

\(17\frac{6}{11}\cdot\frac{4}{27}-8\frac{6}{11}\div\frac{27}{4}+350\%\)

\(=17\frac{6}{11}\cdot\frac{4}{27}-8\frac{6}{11}\cdot\frac{4}{27}+\frac{7}{2}\)

\(=\frac{4}{27}\cdot\left(17\frac{6}{11}-8\frac{6}{11}\right)+\frac{7}{2}\)

\(=\frac{4}{27}\cdot9+\frac{7}{2}\)

\(=\frac{4}{3}+\frac{7}{2}\)

\(=\frac{29}{6}\)

Mọi người đánh giúp mình nhé! Hạn là tối nay!!