Răspuns:
ex 1
15/100×120=15/10×12=15/5×6=90/5=18
ex 2
20/100×x=45
x/5=45
x=45×5=225
ex 3
7÷25=0,28×100=28%
ex 4
x/100×125=75
125x/100=75
5x/4=75
5x=75×4=300
x=300÷5=60%
ex 5
20/100×800=16000/100=160 lei
800+160=960 lei dupa scumpire
20/100×960=960/5=192 lei
960-192=768 lei pret final