x:x+9<xX5<20

1+9<xX5<20

10<xX5<20

2X5<xX5<4X5

x=3

=98 nha ban

X=3 nha bạn

\(x+x.\dfrac{1}{3}+3y=\dfrac{1}{5}\)

\(x.\dfrac{4}{3}+3y=\dfrac{1}{5}\)

\(x.\dfrac{4}{3}=\dfrac{1}{5}-3y\)

\(x=\left(\dfrac{1}{5}-3y\right):\dfrac{4}{3}=\dfrac{3}{20}-\dfrac{9y}{4}\)

x = 4/5 : 3/4

x = 16/15

x = 5/9 : 8/3

x = 5/9 x 3/8

x = 5/24

\(x=\dfrac{4}{5}\times\dfrac{4}{3}\)

\(x=\dfrac{16}{15}\)

-----------------------

\(x=\dfrac{5}{9}\times\dfrac{3}{8}\)

\(x=\dfrac{5}{24}\)

\(x\times\dfrac{3}{4}=\dfrac{4}{5}\)

\(x=\dfrac{4}{5}:\dfrac{3}{4}\)

\(x=\dfrac{4}{5}\times\dfrac{4}{3}\)

\(x=\dfrac{16}{15}\)

\(\dfrac{5}{9}:x=\dfrac{8}{3}\)

      \(x=\dfrac{5}{9}:\dfrac{8}{3}\)

      \(x=\dfrac{5}{9}\times\dfrac{3}{8}\)

     \(x=\dfrac{15}{72}\)

    \(x=\dfrac{5}{24}\)

x/30 + 4/5= 79/30

x/30 = 79/30 - 4/5

x/30= 11/6

11/6= 55/30

=> x= 55

\(x:33=\dfrac{9}{66}\)
\(x=\dfrac{9}{66}\times33\)
\(x=\dfrac{9}{2}\)
\(\dfrac{4}{5}\times x=\dfrac{10}{11}:\dfrac{3}{4}\)
\(\dfrac{4}{5}\times x=\dfrac{40}{33}\)
\(x=\dfrac{40}{33}:\dfrac{4}{5}\)
\(x=\dfrac{50}{33}\)
#Đạt Đang Bận Thở

\(x+\left(x+1\right)+\left(x+2\right)+...+19+20=20\)

\(\Leftrightarrow x+\left(x+1\right)+\left(x+2\right)+...+19=0\)

\(\Leftrightarrow\frac{x\left(19+x\right)}{2}=0\)

\(\Leftrightarrow x\left(x+19\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x=0\\x+19=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=-19\end{cases}}\)

Mà \(x\ne0\)nên \(x=-19\)

\(x-\dfrac{1}{4}=\dfrac{-21}{10}\)

\(x=\dfrac{-21}{10}+\dfrac{1}{4}\)

\(x=\dfrac{-42}{20}+\dfrac{5}{20}=\dfrac{-37}{20}\)

x : 1/3 = 1/2 +1/3

=>x:1/3=5/6

=>x=5/6 x 1/3

=>x=5/18

(x:2/3):2/5=7/10

=>x:2/3=7/10 x 2/5 

=>x:2/3=7/25

=>x=7/25x2/3

=>x=14/75

CHÚC BẠN HỌC TỐT

cái này vừa gửi rồi mà:D

x:1/3=1/2+1/3
x:1/3=5/6
x      =5/6.1/3
x      =5/18
 

(x:2/3):2/5=7/10
x:2/3        =7/10.2/5
x:2/3        =7/25
x:2/3        =7/25.2/3
x:2/3        =14/75
 

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

\(\Rightarrow3\times x=\dfrac{5}{6}\Rightarrow x=\dfrac{5}{18}\)

2) \(\left(x:\dfrac{2}{3}\right):\dfrac{2}{5}=\dfrac{7}{10}\)

\(\Rightarrow\dfrac{3}{2}\times x=\dfrac{7}{10}\times\dfrac{2}{5}=\dfrac{7}{25}\)

\(\Rightarrow x=\dfrac{7}{25}:\dfrac{3}{2}=\dfrac{14}{75}\)

X : 1/3 = 1/2 + 1/3 

X = 5/18

( X : 2/3 ) : 2/5 = 7/10

X = 14/75