Răspuns :
Daca se reduce cu 10% inseamna :
90%*20=
90/100*20=
9/10* 20
-se simplifica 10 si 20 si ramane: 9*2=18 lei
90%*20=
90/100*20=
9/10* 20
-se simplifica 10 si 20 si ramane: 9*2=18 lei
[tex]\mathrm{20- \frac{2\not 0*1\not 0}{1\not 0\not 0} =20-2=}\boxed{\mathrm{18~lei}}[/tex]