Câu 13:
a: \(x+2+\dfrac{2}{5}=4+\dfrac{2}{3}\)
\(\Leftrightarrow x=2-\dfrac{1}{15}=\dfrac{29}{15}\)
b: \(x:2\dfrac{1}{7}=4\dfrac{1}{5}\)
\(\Leftrightarrow x:\dfrac{15}{7}=\dfrac{21}{5}\)
\(\Leftrightarrow x=\dfrac{21}{5}\cdot\dfrac{15}{7}=3\cdot3=9\)