Tìm x a) x - 15/17 = -2/9 . -9/17 b) x - (-3) . 9/(-12) = 6/8

* Hướng dẫn giải

a) 

$\begin{array}{l}x-\frac{15}{17}=\frac{-2}{9}.\frac{-9}{17}\\ x-\frac{15}{17}=\frac{2}{17}\\ x=\frac{2}{17}+\frac{15}{17}\\ x=1\end{array}$

b)

$\begin{array}{l}x-(-3).\frac{9}{(-12)}=\frac{6}{8}\\ x-\frac{9}{4}=\frac{6}{8}\\ x=\frac{6}{8}+\frac{9}{4}\\ x=3\end{array}$