Question

Tìm x biết:

\(\frac{4}{|x-3|+4}=\frac{7}{|15-5x|+2}\)

 

Answer 1

\(\frac{4}{\left|x-3\right|+4}=\frac{7}{\left|15-5x\right|+2}\Leftrightarrow4.\left|15-5x\right|+8=7\left|x-3\right|+28\)

\(\Leftrightarrow4.\left|15-5x\right|-7.\left|x-3\right|=20\)

\(\left|15-5x\right|=\hept{\begin{cases}15-5x\text{ nếu }x\le3\\-15+5x\text{ nếu }x>3\end{cases}}\)

\(\left|x-3\right|=\hept{\begin{cases}x-3\text{ nếu }x>3\\-x+3\text{ nếu }x\le3\end{cases}}\)

bn tự xét tiếp, không làm đc ib