a)

x + 2/5 = 1/2

x          = 1/2 - 2/5

x          = 1/10

b)

x + 3/7 = 2/5 + 3/10

x + 3/7 = 7/10

x         =  7/10 - 3/7

x         = 19/70

c)

19/20 - x = 8/5 - 3/4

19/20 - x = 17/20

x             = 19/20 - 17/20

x             = 1/5

a) x + 2/5 = 1/2 
    x          = 1/2 - 2/5 
    x          = 3/10
b) x + 3/7 = 2/5 + 3/10
    x + 3/7 = 7/10
    x          = 7/10 - 3/7
    x          = 19/70
c) 19/20 - x = 8/5 - 3/4
    19/20 - x = 17/20
                x = 19/20 - 17/20
                x = 2/20 = 1/10

\(\frac{19}{20}-x+\frac{3}{4}=\frac{8}{5}\)

\(\frac{19}{20}-x=\frac{8}{5}-\frac{3}{4}\)

\(\frac{19}{20}-x=\frac{17}{20}\)

\(x=\frac{19}{20}-\frac{17}{20}\)

 \(x=\frac{1}{10}\)

\(\frac{19}{20}-x+\frac{3}{4}=\frac{8}{5}\)

\(1,7-x=1,6\)

\(x=1,7-1,6\)

\(x=0,1\)

a/\(\dfrac{19}{20}-y=\dfrac{8}{5}-\dfrac{3}{4}\)
\(\dfrac{19}{20}-y=\dfrac{17}{20}\)
\(y=\dfrac{19}{20}-\dfrac{17}{20}\)
\(y=\dfrac{2}{20}=\dfrac{1}{10}\)
b/\(y:\dfrac{2}{3}=\dfrac{4}{9}\times3\)
\(y:\dfrac{2}{3}=\dfrac{4}{3}\)
\(y=\dfrac{4}{3}\times\dfrac{2}{3}\)
\(y=\dfrac{8}{9}\)

#データネ

a) 19/20 - y = 8/5 - 3/4

    19/20 - y =   17/20

                y = 17/20 + 19/20

                y =      36/20

b) y : 2/3 = 4/9 x 3

     y : 2/3 = 12/9

          y    =  12/9 x 2/3 

          y    =   24/27

tích cho mik nhaaaaaaaaaaa

Bạn chia từng bài ra được chứ?

\(\dfrac{3}{4}\cdot\dfrac{2}{5}+\dfrac{3}{4}\cdot\dfrac{2}{5}\)

\(=\dfrac{3}{4}\cdot\dfrac{2}{5}\left(1+1\right)\)

\(=\dfrac{6}{20}\cdot2\)

\(=\dfrac{12}{20}=\dfrac{3}{5}\)

3/5 

cái con củ lồn mày

x = 1/10

19/20 - x = 17/20

x = 19/20 - 17/20

x = 2/20

x = 1/10

\(a,x+\dfrac{3}{7}=\dfrac{2}{5}+\dfrac{3}{10}\)

\(x+\dfrac{3}{7}=\dfrac{4}{10}+\dfrac{3}{10}\)

\(x+\dfrac{3}{7}=\dfrac{7}{10}\)

\(x=\dfrac{7}{10}-\dfrac{3}{7}\)

\(x=\dfrac{49}{70}-\dfrac{30}{70}\)

\(x=\dfrac{19}{70}\)

\(b,\dfrac{19}{20}-x=\dfrac{8}{5}-\dfrac{3}{4}\)

\(\dfrac{19}{20}-x=\dfrac{32}{20}-\dfrac{15}{20}\)

\(\dfrac{19}{20}-x=\dfrac{17}{20}\)

\(x=\dfrac{19}{20}-\dfrac{17}{20}\)

\(x=\dfrac{2}{20}\)

\(x=\dfrac{1}{10}\)

#Urushi☕

các bạn làm giúp mình với

a, x + 3/7  = 2/5 - 3/10

    x + 3/7  = 1/10

             x  = 1/10 + 3/7

             x  = 37/70

b, 20/19 - x = 8/5 - 3/4

    20/19 - x = 17/20

                x = 77/380

các bạn k cho mình nha bao giờ trên 11 điểm mình sẽ k lại cho các bạn