Giải phương trình (x+1)/65+(x+3)=(x+5)/61+(x+7)/59

* Hướng dẫn giải

$\begin{array}{l}\frac{x+1}{65}+\frac{x+3}{63}=\frac{x+5}{61}+\frac{x+7}{59}\\ \iff \frac{x+1}{65}+1+\frac{x+3}{63}+1=\frac{x+5}{61}+1+\frac{x+7}{59}+1\iff \frac{x+66}{65}+\frac{x+66}{63}=\frac{x+66}{61}+\frac{x+66}{59}\\ \\ \iff \left(x+66\right)\left(\frac{1}{65}-\frac{1}{63}-\frac{1}{61}-\frac{1}{59}\right)=0\iff x+66=0\iff x=-66\\ \end{array}$