Answer:
Se requiere un 20 por ciento de descuento.
Step-by-step explanation:
(This exercise has been presented in Spanish and for that reason explanation will be held in the same language)
Sea [tex]p_{o}[/tex] el precio original del computador portatil, el nuevo precio es:
[tex]p_{1} =\left(\frac{100\,\% + 25\,\%}{100\,\%} \right)\cdot p_{o}[/tex]
[tex]p_{1} = 1.25\cdot p_{o}[/tex]
Si [tex]p_{2} = p_{o}[/tex], entonces el porcentaje requerido para recuperar el precio original es:
[tex]r = \left(1-\frac{p_{2}}{p_{1}} \right)\times 100\,\%[/tex]
[tex]r = \left(1-\frac{p_{o}}{1.25\cdot p_{o}} \right)\times 100\,\%[/tex]
[tex]r = \left(1-\frac{1}{1.25} \right)\times 100\,\%[/tex]
[tex]r = 20\,\%[/tex]
Se requiere un 20 por ciento de descuento.