\(\dfrac{3}{x+2}=\dfrac{5}{x-3}\left(x\ne-2;x\ne3\right)\)

suy ra: \(3\left(x-3\right)=5\left(x+2\right)\\ < =>3x-9=5x+10\\ < =>3x-5x=10+9\\ < =>-2x=19\\ < =>x=-\dfrac{19}{2}\left(tm\right)\)

\(\dfrac{3}{x+2}=\dfrac{5}{x-3}\)ĐKXĐ \(\left\{{}\begin{matrix}x+2\ne0\\x-3\ne0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x\ne-2\\x\ne3\end{matrix}\right.\)

\(\Leftrightarrow\dfrac{3\left(x-3\right)}{\left(x+2\right)\left(x-3\right)}=\dfrac{5\left(x+2\right)}{\left(x+2\right)\left(x-3\right)}\)

`<=> 3(x-3) =5 (x+2)`

`<=> 3x-9 = 5x+10`

`<=>3x -5x=10+9`

`<=> -2x=19`

`<=>x=-19/2`

\(\dfrac{3}{x+2}=\dfrac{5}{x-3}\text{ĐKXĐ}:x\ne-2;3\)

\(\Leftrightarrow\dfrac{3\left(x-3\right)}{\left(x+2\right)\left(x-3\right)}=\dfrac{5\left(x+2\right)}{\left(x+2\right)\left(x-3\right)}MTC:\left(x+2\right)\left(x-3\right)\)

\(\Rightarrow3x-9=5x+10\)

\(\Leftrightarrow3x-9-5x-10=0\)

\(\Leftrightarrow-2x-19=0\)

\(\Leftrightarrow-2x=19\)

\(\Leftrightarrow x=\dfrac{-19}{2}\left(\text{nhận}\right)\)

\(\text{Vậy phương trình có tập nghiệm là }S=\left\{\dfrac{-19}{2}\right\}\)

\(\frac{3}{-5}=\frac{-3}{5}\)  

\(\Rightarrow\)\(\frac{-3}{5}=\frac{-6}{10}=\frac{-9}{15}=\frac{-15}{25}=\frac{-18}{30}\)

\(\dfrac{3}{7}x=\dfrac{2}{3}\)

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

\(\Rightarrow x=\dfrac{14}{9}\)

2/3 : 3/7

ticks mình nha

\(\left(\dfrac{3}{4}+\dfrac{2}{3}\right):\dfrac{17}{4}-\dfrac{3}{4}\)

\(=\left(\dfrac{9}{12}+\dfrac{8}{12}\right):\dfrac{17}{4}-\dfrac{3}{4}\)

\(=\dfrac{17}{12}:\dfrac{17}{4}-\dfrac{3}{4}\)

\(=\dfrac{17.4}{17.12}-\dfrac{3}{4}\)

\(=\dfrac{1}{3}-\dfrac{3}{4}\)

\(=\dfrac{4}{12}-\dfrac{9}{12}\)

\(=-\dfrac{5}{12}\)

3/4 cm3=750dm3

vì 3/4 x 1000 = 750 

kb nha

0.000075

3 phần 4 cm3 = 0,00075 dm3