Práctica 0 ejercicio 1k - versión 2017

EJERCICIO 1: Calcule

(k) $ \left(\dfrac{1}{8}+\dfrac{2}{5} \right)\left(\dfrac{5}{2}:\dfrac{1}{4} \right)$

Solución:

\begin{eqnarray*}
\left(\dfrac{1}{8}+\dfrac{2}{5} \right)\left(\dfrac{5}{2}:\dfrac{1}{4} \right) & = & \left(\dfrac{5+16}{40}\right)\left(\dfrac{5}{\cancel{2}}\cdot\dfrac{\stackrel{2}{\cancel{4}}}{1} \right) \\
& = & \dfrac{21}{40} \cdot 10 \\
& = & \dfrac{21}{4} \\
\end{eqnarray*}

$$\boxed{ \left(\dfrac{1}{8}+\dfrac{2}{5} \right)\left(\dfrac{5}{2}:\dfrac{1}{4} \right) = \dfrac{21}{4} }$$