Notam pretul initial cu p:
a)
[tex]p+\frac{10}{100} \cdot p=132\\\\\frac{110p}{100}=132\\\\ 110p=13200\\\\p=1320:11=120\ lei[/tex]
b)
[tex]p-\frac{30}{100}\cdot p=147\\\\ \frac{70p}{100}=147\\\\ 7p=1470\\\\p=1470:7=210\ lei[/tex]
c)
[tex](p+\frac{10}{100}\cdot p )+(p+\frac{10}{100}\cdot p)\cdot \frac{10}{100} =363\\\\(p+\frac{1}{10}\cdot p )+(p+\frac{1}{10}\cdot p)\cdot \frac{1}{10} =363\\\\\frac{11p}{10}+ \frac{11p}{10}\cdot \frac{1}{10}=363\\\\ \frac{110p}{100}+\frac{11p}{100}=363\\\\\frac{121p}{100}=363\\\\121p=36300\\\\p=300\ lei[/tex]
d)
[tex](p-\frac{10}{100}\cdot p )-(p-\frac{10}{100}\cdot p)\cdot \frac{10}{100} =162\\\\(p-\frac{1}{10}\cdot p )-(p-\frac{1}{10}\cdot p)\cdot \frac{1}{10} =162\\\\\frac{9p}{10} -\frac{9p}{10} \cdot \frac{1}{10}=162\\\\ \frac{90p}{100} -\frac{9p}{100} =162\\\\\frac{81p}{100} =162\\\\81p=16200\\\\p=200\ lei[/tex]
e)
[tex]p-\frac{20}{100}\cdot p+ (p-\frac{20}{100}\cdot p)\cdot \frac{10}{100}=145,2 \\\\p-\frac{2}{10}\cdot p+ (p-\frac{2}{10}\cdot p)\cdot \frac{1}{10}=145,2 \\\\\frac{8p}{10}+\frac{8p}{100}=145,2\\\\ \frac{88p}{100}=145,2\\\\ 88p=14520\\\\ p=165\ lei[/tex]
Un alt exercitiu gasesti aci: https://brainly.ro/tema/2685363
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