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https://zalo.me/g/eglkxf199

link jz?

tính nhanh hay th bn?

99/2 x 3/5 + 3/5 x 103/2 - 3/5 

= 99/2 x 3/5 + 3/5 x 103/2 - 3/5 x 1

= 3/5 x (99/2 + 103/2 - 1)
= 3/5 x 100

= 60

99/2 x 3/5 + 3/5 x 103/2 - 3/5 

= 99/2 x 3/5 + 3/5 x 103/2 - 3/5 x 1

= 3/5 x (99/2 + 103/2 - 1)
= 3/5 x 100

= 60

Vậy ...

77/45

7/6

29/10

\(\dfrac{3}{5}+\dfrac{4}{3}\times\dfrac{5}{6}=\dfrac{3}{5}+\dfrac{10}{9}=\dfrac{27}{45}+\dfrac{50}{45}=\dfrac{77}{45}\)

\(2-\dfrac{7}{6}+\dfrac{1}{3}=\dfrac{12}{6}-\dfrac{7}{6}+\dfrac{2}{6}=\dfrac{7}{6}\)

\(\dfrac{7}{6}\times3-\dfrac{3}{5}=\dfrac{7}{2}-\dfrac{3}{5}=\dfrac{35}{10}-\dfrac{6}{10}=\dfrac{29}{10}\)

giải chi tiết đi

x - 18 - 42 = 23 - 43 - 70 - x

\(\rightarrow\) 2x = -30

\(\rightarrow\) x = -15

\(\left(-\left(x+15\right)\right)^2\) - 19 = \(3^2\) .5

\(\rightarrow\)\(x^2+30x+225\) - 19 = 45

\(\rightarrow x^2+30x+161=0\)

\(\rightarrow x^2+23x+7x+161=0\)

\(\rightarrow x\left(x+23\right)+7\left(x+23\right)=0\)

\(\rightarrow\left(x+7\right)\left(x+23\right)=0\)

\(\rightarrow\) x = -7 hoặc x = -23

\(\Leftrightarrow\left[3x+6-23\right]\cdot\left(9-8+20\cdot0\right)=147\)

=>3x=164

hay x=164/3

<=> 2x + 3 - 8 + 2x = 5 hoặc -2x - 3 + 8 - 2x = 5 

<=> 4x - 5 = 5 hoặc -4x + 5 = 5 

<=> 4x = 10 hoặc -4x = 0 

<=> x = 5 / 2 hoặc x = 0   

\(\dfrac{2}{3}:x=1,4-\dfrac{12}{5}\)

\(\dfrac{2}{3}:x=\dfrac{7}{5}-\dfrac{12}{5}\)

\(\dfrac{2}{3}:x=-1\)

      \(x=\dfrac{2}{3}:\left(-1\right)\)

      \(x=-\dfrac{2}{3}\)

2/3 : x = -1

x = 2/3 : (-1)

x = -2/3

b) /2/3:x=1,4 - 12/5

    2/3;x=    -7/5

         x=2/3:−75

         x=−1021

\(=\left(\dfrac{3+8}{12}\right)\cdot\dfrac{4}{5}=\dfrac{11}{12}\cdot\dfrac{4}{5}=\dfrac{44}{60}=\dfrac{11}{15}\)