Tìm \(\displaystyle x\) :
a) \(\displaystyle x - \frac{5}{6} = \frac{2}{3}\) b) \(\displaystyle x:\frac{2}{5} = 10\)
\(\displaystyle \begin{array}{l}a) \;x - \dfrac{5}{6} = \dfrac{2}{3}\\ \;\;\;\;x = \dfrac{2}{3} + \dfrac{5}{6} \\ \;\;\;\;x = \dfrac{{9}}{6}=\dfrac{3}{2}\end{array}\)
\(\displaystyle \begin{array}{l}b)\;x:\dfrac{2}{5} = 10\\ \;\;\;\;x{\rm{ }} = {\rm{ }}10 \times \dfrac{2}{5}\\ \;\;\;\;x = 4\end{array}\)
-- Mod Toán lớp 4