1.
[tex] \frac{x}{5} = \frac{12}{3} \\ 5 \times 12 = 3x \\ 60 = 3x \\ x = 20[/tex]
2.
15 litri lapte. 2 kg smântână
x. litri lapte. 3 kg smântână
[tex]x = \frac{15 \times 3}{2} \\ x = 45 \div 2 \\ x = 22.5[/tex]
x=22 litri si jumătate
3. a)
[tex] \frac{14}{100} \times 50 = \frac{14}{10} \times 5 = \frac{14}{2} = 7[/tex]
b)
[tex] \frac{5}{100} x = 18 \\ x = 18 \div \frac{5}{100} \\ x =18 \times \frac{100}{5} \\ x= 18 \times 20 \\ x= 18 \times 10 \times 2 \\ x = 180\times 2 \\ x = 320[/tex]
c)
[tex] \frac{x}{100} \times 70 = 63 \\ \frac{x}{100} = \frac{63}{70} \\ \frac{x}{10} = \frac{63}{7} \\ \frac{x}{10} = 9 \\ x = 9 \times 10 \\ x = 90[/tex]
4.
6 cai. 4 zile
8 cai. x zile
[tex]x = \frac{8 \times 4}{6} \\ x = 32 \div 6 = 5.3[/tex]
8 cai vor manca acel fan in 5 zile si cateva ore
