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13 tháng 4 2023

a) \(\dfrac{-3}{20}\) + \(\dfrac{-7}{4}\) =\(\dfrac{-3}{20}\) + \(\dfrac{-35}{20}\) = -2

b) 6 và \(\dfrac{2}{3}\) - 4 và \(\dfrac{2}{3}\) = 2

c) \(\dfrac{-3}{10}\) + \(\dfrac{7}{12}\) = \(\dfrac{-18}{60}\) + \(\dfrac{35}{60}\) =\(\dfrac{17}{60}\)

d) \(\dfrac{35}{-9}\) . \(\dfrac{81}{7}\) = \(\dfrac{-35}{9}\) . \(\dfrac{81}{7}\) = 45

e) \(\dfrac{-2}{5}\) - \(\dfrac{-3}{4}\) = \(\dfrac{-8}{20}\) - \(\dfrac{-15}{20}\) = \(\dfrac{-8}{20}\) + \(\dfrac{15}{20}\) =\(\dfrac{7}{20}\)

f) \(\dfrac{5}{23}\) . \(\dfrac{7}{26}\) + \(\dfrac{5}{23}\) .\(\dfrac{9}{26}\) = \(\dfrac{5}{23}\) .  ( \(\dfrac{7}{26}\) + \(\dfrac{9}{26}\) )= \(\dfrac{5}{23}\) . \(\dfrac{8}{13}\) = \(\dfrac{40}{299}\)

g) \(\dfrac{-3}{12}\) : \(\dfrac{4}{15}\) =\(\dfrac{-3}{12}\) . \(\dfrac{15}{4}\) =\(\dfrac{-5}{8}\)

h) 1 và \(\dfrac{1}{6}\) - 3 và \(\dfrac{1}{3}\) =\(\dfrac{7}{6}\) -\(\dfrac{10}{3}\) = \(\dfrac{-13}{6}\)

i) \(\dfrac{-2}{5}\) . (-3) + \(\dfrac{3}{8}\) . \(\dfrac{4}{-10}\) =(\(\dfrac{-2}{5}\) .\(\dfrac{-4}{10}\)) + [(-3) . \(\dfrac{3}{8}\) 

                                     = \(\dfrac{4}{25}\) + \(\dfrac{-9}{8}\) = \(\dfrac{32}{200}\) + \(\dfrac{-225}{200}\)  = \(\dfrac{-193}{200}\)

j) \(\dfrac{-13}{17}\) + (\(\dfrac{13}{-21}\) + \(\dfrac{-4}{17}\) )

= ( \(\dfrac{-13}{17}\) + \(\dfrac{-4}{17}\) )+\(\dfrac{-13}{21}\) 

= -1+\(\dfrac{-13}{21}\)

\(\dfrac{-21}{21}\) + \(\dfrac{-13}{21}\) = \(\dfrac{-34}{21}\)

Khôi nguyễn

 

 

13 tháng 4 2023

sao tính nổi:))

 

22 tháng 10 2021

ai trả lời nhanh nhất đc tick nha

22 tháng 10 2021

Bài 2: 

c: \(y:312=345:5\)

\(\Leftrightarrow y:312=69\)

hay \(y=21528\)

d: \(918670-y=251\cdot142\)

\(\Leftrightarrow y=91867-35642=56225\)

a: \(C=\dfrac{-1}{2}:\dfrac{-2}{3}:\dfrac{-3}{4}\)

\(=\dfrac{-1}{2}\cdot\dfrac{3}{-2}\cdot\dfrac{4}{-3}\)

\(=-\dfrac{4}{4}=-1\)

b: \(D=\dfrac{-6}{5}:\dfrac{-5}{4}:\dfrac{-4}{3}\)

\(=-\dfrac{6}{5}\cdot\dfrac{4}{5}\cdot\dfrac{3}{4}\)

\(=\dfrac{-18}{25}\)

c: \(\dfrac{4}{20}+\dfrac{16}{42}+\dfrac{6}{15}+\dfrac{-3}{5}+\dfrac{2}{21}+\dfrac{-10}{21}+\dfrac{3}{20}\)

\(=\left(\dfrac{4}{20}+\dfrac{-3}{5}+\dfrac{6}{15}\right)+\left(\dfrac{16}{42}+\dfrac{2}{21}-\dfrac{10}{21}\right)+\dfrac{3}{20}\)

\(=\left(\dfrac{1}{5}-\dfrac{3}{5}+\dfrac{2}{5}\right)+\left(\dfrac{8}{21}+\dfrac{2}{21}-\dfrac{10}{21}\right)+\dfrac{3}{20}\)

\(=\dfrac{3}{20}\)

d: \(\dfrac{42}{46}+\dfrac{250}{186}+\dfrac{-2121}{2323}+\dfrac{-125125}{143143}\)

\(=\dfrac{21}{23}+\dfrac{125}{93}+\dfrac{-21}{21}+\dfrac{-125}{143}\)

\(=\dfrac{125}{93}-\dfrac{125}{143}=\dfrac{6250}{13299}\)

20 tháng 1 2024

Câu d, chỗ \(\dfrac{-21}{21}\) phải sửa thành \(\dfrac{-21}{23}\)

13 tháng 9 2015

\(5015^{2^{0^{1^3}}}=5015^{2^{0^1}}=5015^{2^0}=5015^1=5015\)

13 tháng 8 2018

a) ( 72 - 8x9 ) : ( 20 + 21 + 22 + 23 + 24 + 25 )

= ( 72 - 72 ) : ( 20 + 21 + 22 + 23 + 24 + 25 )

= 0 : ( 20 + 21 + 22 + 23 + 24 + 25 )

= 0

b) ( 500 x 9 - 250 x 18 ) x ( 1 + 2 + 3 + ... + 9 )

= ( 250 x 2 x 9 - 250 x 18 ) x ( 1 + 2 + 3 + ... + 9 )

= ( 250 x 18 - 250 x 18 ) x ( 1 + 2 + 3 + ... + 9 )

= 0 x ( 1 + 2 + 3 + ... + 9 )

= 0

c ) ( 11 + 13 + 15 + ... + 19 ) x ( 6 x 8 - 48 )

= ( 11 + 13 + 15 + ... + 19 ) x ( 48 - 48 )

= ( 11 + 13 + 15 + ... + 19 ) x 0

= 0

a) ( 72 - 8x9 ) : ( 20 + 21 + 22 + 23 + 24 + 25 )

= ( 72 - 72 ) : ( 20 + 21 + 22 + 23 + 24 + 25 )

= 0 : ( 20 + 21 + 22 + 23 + 24 + 25 )

= 0

26 tháng 7 2017

a)   \(-x+821+534=499+\left(x-84\right)\)

\(-x-x=499-84-821-534\)

\(-2x=-940\)

\(x=470\)

b)  \(x-96=\left(448-x\right)-150\)

\(x+x=448-150+96\)

\(2x=394\)

\(x=197\)

c)  \(-\left(754+x\right)=\left(x-12-741\right)-23\)

\(-754-x=x-12-741-23\)

\(-x+x=-12-741-23+754\)

\(0x=2\)

\(x\)ko tồn tại

d) \(\left(6+x\right)-\left(17-21\right)=-25\)

\(6+x-17+21=-25\)

\(x=-25-6+17-21\)

\(x=-35\)

e)  \(17-\left(x+2\right)=3\)

\(17-x-2=3\)

\(-x=3-17+2\)

\(-x=-12\)

\(x=12\)

h)  \(-10-\left(31-x\right)=40\)

\(-10-31+x=40\)

\(x=40+10+31\)

\(x=81\)

k mk nha bạn    avt202694_60by60.jpg

Nguyễn Thành Đăng
26 tháng 7 2017

a) - x + 821 + 534 = 499 + ( x - 84 )

<=> -x + 821 + 534 = 499 + x - 84

<=> 2x = 940

<=> x = 470

b, x - 96 = ( 448 - x ) - 150

<=> x - 96 = 448 - x - 150

<=> 2x = 394

<=> x = 157

Cac phan con lai tuong tu

26 tháng 7 2017

a) \(-x+821+534=499+\left(x-84\right)\)

\(\Leftrightarrow-x+821+534=499+x-84\)

\(\Leftrightarrow821+534-499+84=x+x\)

\(\Leftrightarrow940=2x\)

\(\Leftrightarrow x=\dfrac{940}{2}\)

\(\Leftrightarrow x=470\)

Vậy \(x=470\)

b) \(x-96=\left(448-x\right)-150\)

\(\Leftrightarrow x-96=448-x-150\)

\(\Leftrightarrow x+x=96+448-150\)

\(\Leftrightarrow2x=394\)

\(\Leftrightarrow x=\dfrac{394}{2}\)

\(\Leftrightarrow x=197\)

Vậy \(x=197\)

c) \(- (754 + x) = (x - 12 - 741) - 23\)

\(\Leftrightarrow-754-x=x-12-741-23\)

\(\Leftrightarrow-754+12+741+23=x+x\)

\(\Leftrightarrow22=2x\)

\(\Leftrightarrow x=\dfrac{22}{2}\)

\(\Leftrightarrow x=11\)

Vậy \(x=11\)

d) \((6 + x) - (17 - 21) = -25\)

\(\Leftrightarrow6+x-17+21=-25\)

\(\Leftrightarrow x=-25-6+17-21\)

\(\Leftrightarrow x=-35\)

Vậy \(x=-35\)

e) \(17-\left(x+2\right)=3\)

\(\Leftrightarrow17-x-2=3\)

\(\Leftrightarrow17-2-3=x\)

\(\Leftrightarrow x=12\)

Vậy \(x=12\)

h) \(-10 - (31 - x) = 40\)

\(\Leftrightarrow-10-31+x=40\)

\(\Leftrightarrow x=40+10+31\)

\(\Leftrightarrow x=81\)

Vậy \(x=81\)

26 tháng 7 2017

a) - x + 821 + 534 = 499 + (x - 84)

= (856 - x) + 499 = 499 + ( x- 84)

=> (x-84) = (856 - x).

= ...

10 tháng 11 2022

Ủa bạn chép vndoc hả, mình cũng vậy