Răspuns
600 de lei
Explicație pas cu pas:
Fie x pretul initial . Dupa prima scumpire pretul devine:
[tex]x+\dfrac{15}{100}\cdot x= x+\dfrac{3}{20}\cdot x=\dfrac{23}{20}\cdot x[/tex]
Dupa a doua scumpire:
[tex]\dfrac{23}{20}\cdot x+\dfrac{20}{100}\cdot \dfrac{23}{20}\cdot x = \dfrac{23}{20}\cdot x+\dfrac{23}{100}\cdot x=\dfrac{138}{100}\cdot x[/tex]
Avem de rezolvat ecuatia:
[tex]\dfrac{138}{100}\cdot x=828\\x=\dfrac{828}{138}\cdot 100\\x=6\cdot 100\\\bold{x=600~lei}[/tex]
