Tìm x biết a) x - -5/6 = 7/12 + -1/4 b) -x -1/9 = -2/45

* Hướng dẫn giải

a) $x-\frac{-5}{6}=\frac{7}{12}+\frac{-1}{4}$

$\begin{array}{l}x=\frac{-5}{6}+\frac{7}{12}+\frac{-1}{4}\\ x=\frac{-1}{2}\end{array}$

b) $-x-\frac{1}{9}=-\frac{2}{45}$

$\begin{array}{l}x=\frac{-1}{9}+\frac{2}{45}\\ x=\frac{-1}{15}\end{array}$