a) ĐKXĐ : \(x\ne0\)
\(\left(-3+\frac{3}{x}-\frac{1}{3}\right):\left(1+\frac{2}{5}+\frac{2}{3}\right)=\frac{-5}{4}\)
\(\left(\frac{-9x}{3x}+\frac{9}{3x}-\frac{x}{3x}\right):\left(\frac{15}{15}+\frac{6}{15}+\frac{10}{15}\right)=\frac{-5}{4}\)
\(\frac{-9x+9-x}{3x}:\frac{15+6+10}{15}=\frac{-5}{4}\)
\(\frac{-10x+9}{3x}:\frac{31}{15}=\frac{-5}{4}\)
\(\frac{-10x+9}{3x}=\frac{-31}{12}\)
\(\Leftrightarrow12\left(-10x+9\right)=-31\cdot3x\)
\(\Leftrightarrow-120x+108=-93x\)
\(\Leftrightarrow-120x+93x=-108\)
\(\Leftrightarrow-27x=-108\)
\(\Leftrightarrow x=4\)
b) ĐKXĐ : \(x\ne0\)
\(\frac{-3x}{4}\cdot\left(\frac{1}{x}+\frac{2}{7}\right)=0\)
\(\Rightarrow\orbr{\begin{cases}\frac{-3x}{4}=0\\\frac{1}{x}+\frac{2}{7}=0\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=0\left(loai\right)\\\frac{-2}{-2x}=\frac{-2}{7}\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=0\left(loai\right)\\x=\frac{-7}{2}\end{cases}}\)
Vậy.....
c) phân tích ra rồi làm thôi e :)) a bận rồi
Trần Thanh Phương làm đúng rồi đó !
k bạn ý đi !
Thôi làm nốt c)
\(3-\frac{1-\frac{1}{2}}{1+\frac{1}{x}}=2\frac{2}{3}\)
\(3-\left[\left(1-\frac{1}{2}\right):\left(1+\frac{1}{x}\right)\right]=\frac{8}{3}\)
\(\frac{1}{2}:\frac{x+1}{x}=\frac{1}{3}\)
\(\frac{1\cdot x}{2\cdot\left(x+1\right)}=\frac{1}{3}\)
\(\frac{x}{2x+2}=\frac{1}{3}\)
\(\Leftrightarrow3x=2x+2\)
\(\Leftrightarrow x=2\)
b) \(-\frac{3x}{4}.\left(\frac{1}{x}+\frac{2}{7}\right)=0\)
\(\Leftrightarrow-\frac{3\left(7+2x\right)}{28}=0\)
\(\Leftrightarrow3\left(7+2x\right)=0\)
\(\Leftrightarrow7+2x=0:3\)
\(\Leftrightarrow7+2x=0\)
\(\Leftrightarrow2x=0-7\)
\(\Leftrightarrow2x=-7\)
\(\Rightarrow x=-\frac{7}{2}\)
c) \(3-\frac{1-\frac{1}{2}}{1+\frac{1}{x}}=2\frac{2}{3}\)
\(\Leftrightarrow3-\frac{x}{2\left(x+1\right)}=2.\frac{2}{3}\)
\(\Leftrightarrow3.2\left(x+1\right)-\frac{x}{2\left(x+1\right)}.2\left(x+1\right)=2.\frac{2}{3}.2\left(x+1\right)\)
\(\Leftrightarrow6\left(x+1\right)-x=\frac{8}{3}\left(x+1\right)\)
\(\Leftrightarrow5x+6=\frac{8}{3}x+\frac{8}{3}\)
\(\Leftrightarrow5x=\frac{8}{3}x+\frac{8}{3}-6\)
\(\Leftrightarrow5x=\frac{-10+8x}{3}\)
\(\Leftrightarrow5x.3=-10+8x\)
\(\Leftrightarrow15x=-10+8x\)
\(\Leftrightarrow7x=-10\)
\(\Rightarrow x=-\frac{10}{7}\)
P/s: k chắc đúng nha
b)
\(\frac{-3x}{4}.\left(\frac{1}{x}+\frac{2}{7}\right)=0\)
TH1:
\(\frac{-3x}{4}=0\Rightarrow-3x=0\Leftrightarrow x=0\)
TH2:
\(\frac{1}{x}+\frac{2}{7}=0\)
\(\frac{1}{x}=\frac{-2}{7}\Rightarrow-2x=7\Rightarrow x=\frac{-7}{2}\)
Vậy...
b)
x = 0 không thỏa mãn đkxđ => loại
Vậy x = -7/2
b) x = 0 không thỏa mãn đkđx => loại . Vậy x = - 7/2
Chúc em hok tốt !
