\(\frac{22}{5}\)\(:\)\(x\)\(=\)\(\frac{44}{5}\)\(:\)\(\frac{5}{2}\)

\(\frac{22}{5}\)\(:\)\(x\)\(=\)\(\frac{88}{25}\)

\(x\)\(=\)\(\frac{22}{5}\)\(:\)\(\frac{88}{25}\)

\(x\)\(=\)\(\frac{5}{4}\)

a) 4/9.x=25/18:2/3

4/9.x=25/18.3/2

4/9.x=75/36

x=75/36:4/9

x=75/36x4/9

x=675/144

b)x:4/5=25/8:5/4

x:4/5=25/8x4/5

x:4/5=100/40

x:4/5=5/2

x=5/2x4/5

x=20/10

x=2/1=2

c)22/5:x=44/5:5/2

22/5:x=44/5x2/5

22/5:x=88/25

x=88/25:22/5

x=88/25x22/5

x=440/550

x=4/5

h nk

\(\frac{22}{5}:x=\frac{44}{5}:\frac{5}{2}\)

\(\frac{22}{5}:x=\frac{44}{5}x\frac{2}{5}\)

\(\frac{22}{5}:x=\frac{88}{25}\)

         \(x=\frac{22}{5}:\frac{88}{25}\)

         \(x=\frac{22}{5}x\frac{25}{88}\)

         \(x=\frac{5}{4}\)

\(\frac{22}{5}:x=\frac{44}{5}:\frac{5}{2}\)

\(\Rightarrow\frac{22}{5}:x=\frac{88}{25}\)

\(\Rightarrow x=\frac{88}{25}\times\frac{22}{5}\)

\(\Rightarrow x=\frac{1936}{125}\)

22/5 : x= 44/5:5/2

22/5 : x = 88/25

          x =  22/5 .  88/25 

            x = 5/4 

a)\(\frac{22}{5}:x=\frac{44}{5}:\frac{5}{2}=\frac{44}{5}.\frac{2}{5}=\frac{84}{25}\)

\(\Rightarrow x=\frac{22}{5}:\frac{84}{25}=\frac{22}{5}.\frac{25}{84}=\frac{55}{42}\)

b) \(8,35x+6,65x=45\)

\(\Rightarrow\left(8,35+6,65\right)x=45\Rightarrow15x=45\)

\(\Rightarrow x=45:15=3\)

\(a,\frac{22}{5}\div x=\frac{44}{5}\div\frac{5}{2}\)

\(\Rightarrow\frac{22}{5}\div x=\frac{88}{25}\)

\(\Rightarrow x=\frac{5}{4}\)

\(b,8,35\times x+6,65\times x=45\)

\(\Rightarrow x\times\left(8,35+6,65\right)=45\)

\(\Rightarrow x\times15=45\)

\(\Rightarrow x=3\)

~Study well~

#Thạc_Trân

a) \(\frac{22}{5}:x=\frac{44}{5}:\frac{5}{2}\)
    \(\frac{22}{5}:x=\frac{88}{25}\)
              \(x=\frac{22}{5}:\frac{88}{25}\)
              \(x=\frac{5}{4}\)
b) \(8,35.x+6,65.x=45\)
  \(\left(8,35+6,65\right).x=45\)
                            \(15.x=45\)
                                   \(x=45:15\)
                                   \(x=3\)
- Dấu . là dấu nhân

A) \(\frac{4}{5}\)x\( y\)=\(\frac{5}{7}:\frac{3}{14}=\frac{10}{3}\)

\(\Rightarrow y=\frac{10}{3}:\frac{4}{5}=\frac{10}{3}.\frac{5}{4}=\frac{25}{6}\)

B) \(\Rightarrow\frac{22}{5}:y=\frac{44}{5}:\frac{5}{2}=\frac{44}{5}.\frac{2}{5}=\frac{88}{25}\)

\(\Rightarrow y=\frac{22}{5}:\frac{88}{25}=\frac{22}{5}.\frac{25}{88}=\frac{5}{4}\)

a)\(x:\frac{9}{22}=44\)                                    b)\(x:\frac{5}{11}=33\)                           c)\(x:\frac{4}{33}=22\)

 \(x\)     \(=44\times\frac{9}{22}\)                        \(x\)       \(=33\times\frac{5}{11}\)                \(x\)       \(=22\times\frac{4}{33}\)    

   \(x\)      \(=18\)                                    \(x\)         \(=15\)                          \(x\)        \(=\frac{8}{3}\)

A) X : 9/22 = 44

              X=44x9/22

              X=18

B) X : 5/11 = 33

              X=33x5/11

              X=15

C) X : 4/33 = 22

              X=22x4/33

              X=8/3

\(x:\frac{9}{22}=44\)

\(x=44X\frac{9}{22}\)

\(x=18\)

vậy X = 18

\(x:\frac{5}{11}=33\)

\(x=33X\frac{5}{11}\)

\(x=15\)

vậy X = 15

\(x:\frac{4}{33}=22\)

\(x=22X\frac{4}{33}\)

\(x=\frac{8}{3}\)

vậy X = \(\frac{8}{3}\)

Bài 1:

a) \(4^{x+2}+4^x=68\)

\(\Rightarrow4^x\cdot\left(4^2+1\right)=68\)

\(\Rightarrow4^x\cdot17=68\)

\(\Rightarrow4^x=\dfrac{68}{17}\)

\(\Rightarrow4^x=4\)

\(\Rightarrow4^x=4^1\)

\(\Rightarrow x=1\)

b) \(5\cdot2^{x+4}-3\cdot2^x=308\)

\(\Rightarrow2^x\cdot\left(5\cdot2^4-3\right)=308\)

\(\Rightarrow2^x\cdot\left(5\cdot16-3\right)=308\)

\(\Rightarrow2^x\cdot77=308\)

\(\Rightarrow2^x=\dfrac{308}{77}\)

\(\Rightarrow2^x=4\)

\(\Rightarrow2^x=2^2\)

\(\Rightarrow x=2\)

c) \(4\cdot3^{x+1}+7\cdot3^x=513\)

\(\Rightarrow3^x\cdot\left(4\cdot3+7\right)=513\)

\(\Rightarrow3^x\cdot19=513\)

\(\Rightarrow3^x=\dfrac{513}{19}\)

\(\Rightarrow3^x=27\)

\(\Rightarrow3^x=3^3\)

\(\Rightarrow x=3\)

d) \(5^{x+4}-5^x=3120\)

\(\Rightarrow5^x\cdot\left(5^4-1\right)=3120\)

\(\Rightarrow5^x\cdot\left(625-1\right)=3120\)

\(\Rightarrow5^x\cdot624=3120\)

\(\Rightarrow5^x\cdot\dfrac{3120}{624}\)

\(\Rightarrow5^x=5\)

\(\Rightarrow5^x=5^1\)

\(\Rightarrow x=1\)

f) \(3\cdot4^{2x+1}-16^x=2816\)

\(\Rightarrow3\cdot4^{2x+1}-\left(4^2\right)^x=2816\)

\(\Rightarrow3\cdot4^{2x+1}-4^{2x}=2816\)

\(\Rightarrow4^{2x}\cdot\left(3\cdot4-1\right)=2816\)

\(\Rightarrow4^{2x}\cdot11=2816\)

\(\Rightarrow4^{2x}=\dfrac{2816}{11}\)

\(\Rightarrow4^{2x}=256\)

\(\Rightarrow\left(2^2\right)^{2x}=2^8\)

\(\Rightarrow2^{4x}=2^8\)

\(\Rightarrow4x=8\)

\(\Rightarrow x=2\)

Bài 2:

\(2^x+124=5^y\)

\(\Rightarrow5^y-2^x=124\)

\(\Rightarrow5^y-2^x=125-1\)

\(\Rightarrow\left\{{}\begin{matrix}5^y=125\\2^x=1\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}5^y=5^3\\2^x=2^0\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}y=3\\x=0\end{matrix}\right.\)

Vậy: .... 

Bài 3 là hỗn số hả em?

Bài 1: 

a) Ta có: \(\dfrac{2}{5}\cdot x+\dfrac{1}{3}=\dfrac{1}{5}\)

\(\Leftrightarrow\dfrac{2}{5}\cdot x=\dfrac{1}{5}-\dfrac{1}{3}=\dfrac{-2}{15}\)

\(\Leftrightarrow x=\dfrac{-2}{15}:\dfrac{2}{5}=\dfrac{-2}{15}\cdot\dfrac{5}{2}\)

hay \(x=-\dfrac{1}{3}\)

Vậy: \(x=-\dfrac{1}{3}\)

b) Ta có: \(\dfrac{1}{5}+\dfrac{5}{3}:x=\dfrac{1}{2}\)

\(\Leftrightarrow\dfrac{5}{3}:x=\dfrac{1}{2}-\dfrac{1}{5}=\dfrac{3}{10}\)

\(\Leftrightarrow x=\dfrac{5}{3}:\dfrac{3}{10}=\dfrac{5}{3}\cdot\dfrac{10}{3}\)

hay \(x=\dfrac{50}{9}\)

Vậy: \(x=\dfrac{50}{9}\)

c) Ta có: \(\dfrac{4}{9}-\dfrac{5}{3}\cdot x=-2\)

\(\Leftrightarrow\dfrac{5}{3}x=\dfrac{4}{9}+2=\dfrac{22}{9}\)

\(\Leftrightarrow x=\dfrac{22}{9}:\dfrac{5}{3}=\dfrac{22}{9}\cdot\dfrac{3}{5}\)

hay \(x=\dfrac{22}{15}\)

Vậy: \(x=\dfrac{22}{15}\)

d) Ta có: \(\dfrac{5}{7}:x-3=\dfrac{-2}{7}\)

\(\Leftrightarrow\dfrac{5}{7}:x=\dfrac{-2}{7}+3=\dfrac{19}{21}\)

\(\Leftrightarrow x=\dfrac{5}{7}:\dfrac{19}{21}=\dfrac{5}{7}\cdot\dfrac{21}{19}\)

hay \(x=\dfrac{15}{19}\)

Vậy:\(x=\dfrac{15}{19}\)