\(a,\dfrac{x}{3}=\dfrac{10}{15}\\ \Rightarrow\dfrac{x}{3}=\dfrac{2}{3}\\ \Rightarrow x=2\\ b,\dfrac{x}{5}=\dfrac{26}{65}\\ \Rightarrow\dfrac{x}{5}=\dfrac{2}{5}\\ \Rightarrow x=2\)
a, \(\dfrac{x}{3}=\dfrac{10}{15}\Leftrightarrow\dfrac{5x}{15}=\dfrac{10}{15}\Rightarrow x=2\)
b, \(\dfrac{x}{5}=\dfrac{26}{65}\Leftrightarrow\dfrac{13x}{65}=\dfrac{26}{65}\Rightarrow x=2\)