Bună,:)
15)
[tex] \frac{4}{2} = 2[/tex]
[tex] \frac{6}{3} = 2[/tex]
[tex] \frac{12}{6} = 2[/tex]
16)
12 kg...............9 kg dulceață
4 kg ...............x kg dulceață
_________________________
[tex]x = \frac{4 \times 9}{12} = \frac{36}{12} = 3 \: kg \: (dulceata)[/tex]
17)
10 muncitori ...................7 zile
5 muncitori ..................... x zile
___________________________
[tex]x = \frac{5 \times 7}{10} = \frac{35}{10} = 3.5 \: zile[/tex]
10 muncitori ................ 7 zile
20 muncitori ............... x zile
[tex]x = \frac{20 \times 7}{10} = \frac{140}{10} = 14 \: (zile)[/tex]
18)
18 muncitori .................. 8 zile
16 muncitori .................. x zile
__________________________
[tex]x = \frac{16 \times 8}{18} = \frac{128}{18} = 7.1 \: (zile)[/tex]
19)
{a,b,c} d.p.{x,y,z}
[tex] \frac{a}{x} = \frac{b}{y} = \frac{c}{z} [/tex]
20)
{a,b}d.p.{2,3}
a+b=25
[tex] \frac{ a}{2} = \frac{b}{3} = k = > a = 2k \\ b = 3k[/tex]
2k+3k=25=>k=5=>a=10
b=15
21)
{a,b}d.p.{1/3;1/5}
a+b=56
[tex] \frac{a}{3} = \frac{b}{5} = k = > a = 3k \\ b = 5k[/tex]
8k=56=>k=7
a=21 b=35
