Chuyển dấu '' - '' của -7/12 sang cho 4/19 thứ 2

=> -4/9 x ( 5/12 + 7/12 ) - 15/19

= -4/9 x 1 - 15/19

= -4/9 - 15/9

= -19/9

d: \(-37\cdot\left(-19\right)+37\left(-19\right)\)

\(=-19\left(-37+37\right)\)

\(=-19\cdot0=0\)

e: \(\left(29-9\right)\cdot\left(-9\right)+\left(-13-7\right)\cdot21\)

\(=20\cdot\left(-9\right)+\left(-20\right)\cdot21\)

\(=-20\left(9+21\right)\)

\(=-20\cdot30=-600\)

h: \(12\cdot\left(-47\right)+12\left(-19\right)+\left(-66\right)\cdot88\)

\(=12\left(-47-19\right)+\left(-66\right)\cdot88\)

\(=\left(-66\right)\cdot12+\left(-66\right)\cdot88\)

\(=-66\left(12+88\right)\)

\(=-66\cdot100=-6600\)

=-19x100=-1900

=(12.(-19)+(-19).87)-19

=-19(12+87)-19

=-19.99-19

=-1878-19

=-1907

a) \(\dfrac{25}{37}\times\dfrac{18}{29}+\dfrac{18}{29}\times\dfrac{12}{37}\)

\(=\dfrac{18}{29}\times\left(\dfrac{25}{37}+\dfrac{12}{37}\right)\)

\(=\dfrac{18}{29}\times\dfrac{37}{37}\)

\(=\dfrac{18}{29}\times1\)

\(=\dfrac{18}{29}\)

b) \(\dfrac{31}{85}\times\dfrac{11}{19}+\dfrac{31}{85}\times\dfrac{12}{19}-\dfrac{42}{19}\times\dfrac{31}{85}\)

\(=\dfrac{31}{85}\times\left(\dfrac{11}{19}+\dfrac{12}{19}-\dfrac{42}{19}\right)\)

\(=\dfrac{31}{85}\times\dfrac{-19}{19}\)

\(=\dfrac{31}{85}\times-1\)

\(=-\dfrac{31}{85}\)

c) \(\dfrac{16}{53}:\dfrac{17}{9}-\dfrac{16}{53}:\dfrac{17}{8}\)

\(=\dfrac{16}{53}:\left(\dfrac{9}{17}-\dfrac{8}{17}\right)\)

\(=\dfrac{16}{53}:\dfrac{1}{17}\)

\(=\dfrac{16}{901}\)

c) \(\dfrac{1}{5}\times\dfrac{12}{31}\times\dfrac{4}{3}+\dfrac{19}{31}\times\dfrac{4}{15}\)

\(=\dfrac{4}{15}\times\dfrac{12}{31}+\dfrac{19}{31}\times\dfrac{4}{15}\)

\(=\dfrac{4}{15}\times\left(\dfrac{12}{31}+\dfrac{19}{31}\right)\)

\(=\dfrac{4}{15}\times\dfrac{31}{31}\)

\(=\dfrac{4}{15}\times1\)

\(=\dfrac{4}{15}\)

a: =18/29*(25/37+12/37)

=18/29

b: =31/85(11/19+12/19-42/19)

=-31/85

c; =16/53(9/17+8/17)=16/53

d: =4/15(12/31+19/31)=4/15

63 / 19

=\(\frac{63}{19}\)nhé

= 811123,1263612567352132183321213 đó

rảnh đi ngồi hành hạ cái bàn phím, ghê ta

chế nào thấy thương cái bộ bàn phím thì đi qua nhớ em nhá

\(\frac{7}{19}\times\frac{8}{11}+\frac{7}{19}\times\frac{3}{11}+\frac{12}{19}\)

\(=\frac{7}{19}\times\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{12}{19}\)

\(=\frac{7}{19}\times\frac{11}{11}+\frac{12}{19}\)

\(=\frac{7}{19}\times1+\frac{12}{19}\)

\(=\frac{7}{19}+\frac{12}{19}\)

\(=\frac{19}{19}\)

\(=1\)

Chúc bạn học tốt

A = (7/19 + 12/9)- 8/11+ 7/19 :3/11

A = 1 - 8/11 + 7/19 : 3/11

A = 3/11 + 7/19 : 3/11

A = 1018/627