Fie proportia [tex] \frac{a}{b} = \frac{c}{d} [/tex],in cazul nostru [tex] \frac{0,5}{3} = \frac{4}{24} [/tex].
Se pot scrie asa:[tex]1.Proportii~derivate~cu~aceasi~termeni:\\\\ a)\frac{3}{0,5} = \frac{24}{4} (inversam~cele~doua~rapoarte)\\\\
b) \frac{0,5}{3} = \frac{3}{24} (schimbam~mezii~intre~ei)\\\\
c) \frac{24}{3} = \frac{0,5}{4} (schimbam~extremii~intre~ei)\\
[/tex][tex]2.Proportii~cu~termeni~schimbati:\\\\
a) \frac{0,5}{0,5+3} = \frac{4}{4+24} (adunam~din~numitori)\\
\frac{0,5}{0,5-3} = \frac{4}{24-4} (scadem~din~numitori)\\\\
b) \frac{0,5+3}{3} = \frac{24+4}{4} (adunam~la~numaratori)\\
\frac{0,5-3}{3} = \frac{4-24}{4} (scadem~la~numatori)
[/tex]
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0,5+4=0,5 sau 0,5-4=0,5 (adunam/scadem numitorii si numaratorii)
3+24 3 3-24 3
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0,5x=4x sau 0,5=4 (inmultim/impartim numaratorii sau numaratorii
3 24 3x 24x cu acelasi numar nenul,adica diferit de 0)
