a.\(\dfrac{5}{3}x-2\dfrac{1}{3}=-\dfrac{4}{3}.1\dfrac{1}{8}-\dfrac{2}{3}\)

\(\dfrac{5}{3}x-2\dfrac{1}{3}=\dfrac{5}{6}\)

\(\dfrac{5}{3}x=\dfrac{5}{6}+2\dfrac{1}{3}\)

\(\dfrac{5}{3}x=\dfrac{19}{6}\)

\(x=\dfrac{19}{5}:\dfrac{5}{3}\)

\(x=\dfrac{19}{10}\)

b. \(2\dfrac{1}{6}:x-\dfrac{-5}{8}=\dfrac{-7}{15}:4\dfrac{1}{5}-\dfrac{-6}{7}\)

\(2\dfrac{1}{6}:x+\dfrac{5}{8}=\dfrac{47}{63}\)

\(2\dfrac{1}{6}:x=\dfrac{47}{63}-\dfrac{5}{8}\)

\(2\dfrac{1}{6}:x=\dfrac{61}{504}\)

\(x=2\dfrac{1}{6}:\dfrac{61}{504}\)

\(x=\dfrac{1092}{61}\)

a, \(\dfrac{5}{3}x-2\dfrac{1}{3}=-\dfrac{4}{3}.1\dfrac{1}{8}-\dfrac{2}{3}\)

\(\Rightarrow\dfrac{5}{3}x=-\dfrac{3}{2}-\dfrac{2}{3}+2\dfrac{1}{3}=-\dfrac{3}{2}+2=\dfrac{1}{2}\)

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

b, \(2\dfrac{1}{6}:x-\dfrac{-5}{8}=\dfrac{-7}{15}:4\dfrac{1}{5}-\dfrac{-6}{7}\)

\(\Rightarrow\dfrac{13}{6}:x=-\dfrac{7}{15}:\dfrac{21}{5}+\dfrac{6}{7}-\dfrac{5}{8}\)

\(\Rightarrow\dfrac{13}{6}:x=\dfrac{61}{504}\Rightarrow x=\dfrac{1092}{61}\)

c, \(\left(\dfrac{5}{6}x-0,3\right):2\dfrac{1}{3}=25\%\)

\(\Rightarrow\dfrac{5}{6}x-0,3=\dfrac{1}{4}.\dfrac{7}{3}\)

\(\Rightarrow\dfrac{5}{6}x=\dfrac{7}{12}+0,3=\dfrac{53}{60}\)

\(\Rightarrow x=\dfrac{53}{60}:\dfrac{5}{6}=1,06\)

d, \(\dfrac{4}{7}-\dfrac{2}{3}x=1,5+\dfrac{4}{5}x\)

\(\Rightarrow\dfrac{4}{5}x+\dfrac{2}{3}x=\dfrac{4}{7}-1,5\)

\(\Rightarrow\dfrac{22}{15}x=-\dfrac{13}{14}\Rightarrow x=-\dfrac{195}{308}\)

Chúc bạn học tốt!!!

Giải:

a) \(\left(\dfrac{1}{3}.x\right):\dfrac{2}{3}=1\dfrac{3}{4}:\dfrac{2}{5}\)

\(\Leftrightarrow\left(\dfrac{1}{3}x\right):\dfrac{2}{3}=\dfrac{7}{4}:\dfrac{2}{5}\)

\(\Leftrightarrow\left(\dfrac{1}{3}x\right):\dfrac{2}{3}=\dfrac{35}{8}\)

\(\Leftrightarrow\dfrac{1}{3}x=\dfrac{35}{8}.\dfrac{2}{3}\)

\(\Leftrightarrow\dfrac{1}{3}x=\dfrac{35}{12}\)

\(\Leftrightarrow x=\dfrac{35}{12}:\dfrac{1}{3}\)

\(\Leftrightarrow x=\dfrac{35}{4}\)

Vậy \(x=\dfrac{35}{4}\).

b) \(4,5:0,3=2,25\left(0,1.x\right)\)

\(\Leftrightarrow15=2,25\left(0,1.x\right)\)

\(\Leftrightarrow2,25\left(0,1.x\right)=15\)

\(\Leftrightarrow0,1.x=\dfrac{15}{2,25}\)

\(\Leftrightarrow0,1.x=\dfrac{20}{3}\)

\(\Leftrightarrow x=\dfrac{20}{3}:0,1\)

\(\Leftrightarrow x=\dfrac{200}{3}\)

Vậy \(x=\dfrac{200}{3}\).

c) \(8:\left(\dfrac{1}{4}.x\right)=2:0,02\)

\(\Leftrightarrow8:\left(\dfrac{1}{4}.x\right)=100\)

\(\Leftrightarrow\dfrac{1}{4}.x=\dfrac{2}{25}\)

\(\Leftrightarrow x=\dfrac{2}{25}:\dfrac{1}{4}\)

\(\Leftrightarrow x=\dfrac{8}{25}\)

Vậy \(x=\dfrac{8}{25}\).

d) \(3:2\dfrac{1}{4}=\dfrac{3}{4}:\left(6.x\right)\)

\(\Leftrightarrow3:\dfrac{9}{4}=\dfrac{3}{4}:\left(6.x\right)\)

\(\Leftrightarrow\dfrac{4}{3}=\dfrac{3}{4}:\left(6.x\right)\)

\(\Leftrightarrow\dfrac{4}{3}:\left(6.x\right)=\dfrac{3}{4}\)

\(\Leftrightarrow6.x=\dfrac{4}{3}:\dfrac{3}{4}\)

\(\Leftrightarrow6.x=\dfrac{16}{9}\)

\(\Leftrightarrow x=\dfrac{16}{9}:6\)

\(\Leftrightarrow x=\dfrac{8}{27}\)

Vậy \(x=\dfrac{8}{27}\).

Chúc bạn học tốt!!!

Bai 1: \(\left(-2\right)^3.\left(\dfrac{3}{4}-0,25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\)

\(=\left(-8\right).\left(\dfrac{3}{4}-\dfrac{1}{4}\right):\left(\dfrac{9}{4}-\dfrac{7}{6}\right)\)

\(=\left(-8\right).\dfrac{1}{2}:\left(\dfrac{27}{12}-\dfrac{14}{12}\right)\)

\(=\left(-4\right):\dfrac{13}{12}\)

\(=\left(-4\right).\dfrac{12}{13}\)

\(=\dfrac{-48}{13}\)

Bai 2:

\(a,4\dfrac{1}{3}:\dfrac{x}{4}=6:0,3\)

\(\dfrac{13}{3}:\dfrac{x}{4}=20\)

\(\dfrac{x}{4}=\dfrac{13}{3}:20\)

\(\dfrac{x}{4}=\dfrac{13}{60}\)

➩ \(x.60=4.13\) ➩ \(x.60=52\) ➩ \(x=\dfrac{13}{15}\)

Vay \(x=\dfrac{13}{15}\)

\(b,\left(2^3:4\right).2^{\left(x+1\right)}=64\)

\(\left(8:4\right).2^{x+1}=64\)

\(2.2^{x+1}=64\)

\(2^{x+1}=32\)

➩ \(2^{x+1}=2^5\) ➩ \(x+1=5\) ➩ \(x=4\)

Vay \(x=4\)

b) \(\dfrac{4}{5}-\dfrac{3}{4}:x=0,3\)

\(\Rightarrow0,8-0,75:x=0,3\)

\(\Rightarrow0,75:x=0,5\)

\(\Rightarrow x=1,5\)

c) \(\dfrac{-3}{2}-\dfrac{1}{4}x=1\dfrac{1}{3}-0,2x\)

\(\Rightarrow\dfrac{-3}{2}-\dfrac{4}{3}=\dfrac{1}{4}x-\dfrac{1}{5}x\)

\(\Rightarrow x=\dfrac{-17}{6}\cdot20\)

\(\Rightarrow x=\dfrac{-170}{3}\)

d) \(\left|\dfrac{3}{5}x+\dfrac{4}{3}\right|:\dfrac{2}{3}-0,5=1\dfrac{1}{2}\)

\(\Rightarrow\left|\dfrac{3}{5}x+\dfrac{4}{3}\right|:\dfrac{2}{3}=\dfrac{3}{2}+\dfrac{1}{2}\)

.\(\Rightarrow\left|\dfrac{3}{5}x+\dfrac{4}{3}\right|=\dfrac{4}{3}\)

\(\Rightarrow\left[{}\begin{matrix}\dfrac{3}{5}x+\dfrac{4}{3}=\dfrac{4}{3}\Rightarrow x=0\\\dfrac{3}{5}x+\dfrac{4}{3}=-\dfrac{4}{3}\Rightarrow x=\dfrac{-40}{9}\end{matrix}\right.\)

ai giúp với mình sắp đi học rồi

\(B=\dfrac{\dfrac{2}{10}-\dfrac{3}{8}+\dfrac{5}{11}}{\dfrac{-3}{10}+\dfrac{9}{16}-\dfrac{15}{22}}\)\(-\dfrac{1}{3}\)

\(B=\dfrac{\dfrac{2}{10}-\dfrac{6}{16}+\dfrac{10}{22}}{\dfrac{-3}{10}+\dfrac{9}{16}-\dfrac{15}{22}}\)\(-\dfrac{1}{3}\)

\(B=\dfrac{2.\left(\dfrac{1}{10}-\dfrac{3}{16}+\dfrac{5}{22}\right)}{-3.\left(\dfrac{1}{10}-\dfrac{3}{16}+\dfrac{5}{22}\right)}\)\(-\dfrac{1}{3}\)

\(B=\dfrac{-2}{3}-\dfrac{1}{3}=-1\)

6)a) \(\left|\dfrac{5}{3}:x\right|=\left|\dfrac{-1}{6}\right|\)

⇒ \(\left|\dfrac{5}{3}:x\right|=\dfrac{1}{6}\)

⇒ \(\dfrac{5}{3}:x=\dfrac{1}{6}\) hoặc \(\dfrac{5}{3}:x=\dfrac{-1}{6}\)

*TH1 : \(\dfrac{5}{3}:x=\dfrac{1}{6}\)

⇒ \(x=\dfrac{5}{3}:\dfrac{1}{6}=10\)

*TH2 : \(\dfrac{5}{3}:x=\dfrac{-1}{6}\)

⇒ \(x=\dfrac{5}{3}:\dfrac{-1}{6}=-10\)

Vậy \(x\) ∈ \(\left\{10;-10\right\}\)

\(b,\left|\dfrac{3}{4}x-\dfrac{3}{4}\right|-\dfrac{3}{4}=\left|\dfrac{-3}{4}\right|\)

⇒ \(\left|\dfrac{3}{4}x-\dfrac{3}{4}\right|-\dfrac{3}{4}=\dfrac{3}{4}\)

⇒\(\left|\dfrac{3}{4}x-\dfrac{3}{4}\right|=\dfrac{3}{4}+\dfrac{3}{4}=\dfrac{3}{2}\)

⇒ \(\dfrac{3}{4}x-\dfrac{3}{4}=\dfrac{3}{2}\) hoặc \(\dfrac{3}{4}x-\dfrac{3}{4}=\dfrac{-3}{2}\)

TH1 : \(\dfrac{3}{4}x-\dfrac{3}{4}=\dfrac{3}{2}\)

⇒ \(\dfrac{3}{4}x=\dfrac{3}{2}+\dfrac{3}{4}=\dfrac{9}{4}\)

⇒\(x=\dfrac{9}{4}:\dfrac{3}{4}=3\)

TH2 : \(\dfrac{3}{4}x-\dfrac{3}{4}=\dfrac{-3}{2}\)

⇒ \(\dfrac{3}{4}x=\dfrac{-3}{2}+\dfrac{3}{4}=\dfrac{-3}{4}\)

⇒ \(x=\dfrac{-3}{4}:\dfrac{3}{4}=-1\)

Vậy \(x\) ∈ \(\left\{3;1\right\}\)

\(\dfrac{8^{14}}{4^4.64^5}=\dfrac{\left(2^3\right)^{14}}{\left(2^2\right)^4.\left(2^5\right)^5}=\dfrac{2^{42}}{2^8.2^{25}}=2^{42-\left(8+25\right)}=2^9\)

\(\dfrac{9^{10}.27^7}{81^7.3^{15}}=\dfrac{\left(3^2\right)^{10}.\left(3^3\right)^7}{\left(3^4\right)^7.3^{15}}=\dfrac{3^{20}.3^{21}}{3^{28}.3^{15}}=\dfrac{3^{20+21}}{3^{28+15}}=\dfrac{3^{41}}{3^{41}.3^2}=\dfrac{1}{3^2}=\dfrac{1}{9}\)

1/

Áp dụng tính chất của dãy tỉ số bằng nhau, ta có:

\(\dfrac{x}{5}=\dfrac{y}{6}=\dfrac{x-y}{5-6}=\dfrac{36}{-1}=-36\)

\(\Rightarrow\left\{{}\begin{matrix}x=-36\cdot5=-180\\y=-36\cdot6=-216\\z=-36\cdot4=-144\end{matrix}\right.\)

2/

Áp dụng tính chất của dãy tỉ số bằng nhau, ta có:

\(\dfrac{y}{3}=\dfrac{z}{4}=\dfrac{y+z}{3+4}=\dfrac{28}{7}=4\)

\(\Rightarrow\left\{{}\begin{matrix}x=4\cdot7=28\\y=4\cdot3=12\\z=4\cdot4=16\end{matrix}\right.\)

3/

\(\dfrac{x}{1,2}=\dfrac{y}{1,3}\Leftrightarrow\dfrac{2x}{2,4}=\dfrac{y}{1,3}\)

Áp dụng tính chất của dãy tỉ số bằng nhau, ta có:

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

\(\Rightarrow\left\{{}\begin{matrix}x=\dfrac{5\cdot2,4}{2}=6\\y=5\cdot1,3=6,5\\z=5\cdot1,4=7\end{matrix}\right.\)

4/

Áp dụng tính chất của dãy tỉ số bằng nhau, ta có:

\(\dfrac{x}{0,5}=\dfrac{y}{0,3}=\dfrac{x-y}{0,5-0,3}=\dfrac{1}{0,2}=5\)

\(\Rightarrow\left\{{}\begin{matrix}x=5\cdot0,5=2,5\\y=5\cdot0,3=1,5\\z=5\cdot0,2=1\end{matrix}\right.\)

5/

\(z=\dfrac{x}{0,3}\Leftrightarrow z=\dfrac{3x}{0,9}\)

Áp dụng tính chất của dãy tỉ số bằng nhau, ta có:

\(z=\dfrac{3x}{0,9}=\dfrac{z-3x}{1-0,9}=\dfrac{1}{0,1}=10\)

\(\Rightarrow\left\{{}\begin{matrix}x=\dfrac{10\cdot0,9}{3}=3\\y=10\cdot0,7=7\\z=10\end{matrix}\right.\)

a) \(4\dfrac{1}{3}:\dfrac{x}{4}=6:0,3\)

\(\dfrac{13}{3}:\dfrac{x}{4}=20\)

\(\dfrac{x}{4}=\dfrac{13}{3}:20\)

\(\dfrac{x}{4}=\dfrac{13}{3}\cdot\dfrac{1}{20}\)

\(\dfrac{x}{4}=\dfrac{13}{60}\)

\(x=\dfrac{13}{60}\cdot4\)

Vậy \(x=\dfrac{13}{15}\)

b)\(2^3:4.2^{\left(x+1\right)}=64\)

\(8:4.2^{\left(x+1\right)}=64\)

\(2.2^{\left(x+1\right)}=64\)

\(2\cdot2^x.2=64\)

\(4.2^x=64\)

\(2^x=64:4\)

\(2^x=16\)

\(2^x=2^4\)

Vậy \(x=4\)

Tìm x

a) x= \(\frac{13}{15}\)

b) x= 4

Chúc bạn học tốt

a, x = \(\dfrac{13}{15}\)

b, x =4