\(\frac{150}{x-1}-\frac{140}{x}=5\)
\(\Leftrightarrow\frac{150}{x-1}.x\left(x-1\right)-\frac{140}{x}.x\left(x-1\right)=5.x\left(x-1\right)\)
\(\Leftrightarrow150x-140\left(x-1\right)=5x\left(x-1\right)\)
\(\Leftrightarrow10x+140=5x^2-5x\)
\(\Leftrightarrow5x^2-5x=10x+140\)
\(\Leftrightarrow5x^2-5x-140=10x+140-140\)
\(\Leftrightarrow5x^2-5x-140=10x\)
\(\Leftrightarrow5x^2-5x-140=10x-10\)
\(\Leftrightarrow5x^2-5x-140=0\)
\(\Rightarrow\hept{\begin{cases}x=7\\x=-4\end{cases}}\)
Không chắc nha
\(ĐKXĐ:x\ne1\)
\(\frac{150}{x-1}-\frac{140}{x}=5\)
\(\Leftrightarrow\frac{150x}{x\left(x-1\right)}-\frac{140\left(x-1\right)}{x\left(x-1\right)}=5\)
\(\Leftrightarrow\frac{150x}{x\left(x-1\right)}-\frac{140x-140}{x\left(x-1\right)}=5\)
\(\Leftrightarrow\frac{150x-140x+140}{x\left(x-1\right)}=5\)
\(\Leftrightarrow150x-140x+140=5x\left(x-1\right)\)
\(\Leftrightarrow10x+140=5x\left(x-1\right)\)
\(\Leftrightarrow10\left(x+14\right)=5x\left(x-1\right)\)
\(\Leftrightarrow2\left(x+14\right)=x\left(x-1\right)\)
\(\Leftrightarrow2x+28=x^2-x\)
\(\Leftrightarrow3x+28=x^2\)
\(\Leftrightarrow3x-x^2=-28\)
\(\Leftrightarrow x\left(3-x\right)=-28\)
\(\Leftrightarrow x\left(3-x\right)=-4.7\)
\(\Leftrightarrow x=-4\)
