Răspuns:
12)
[tex] \frac{x}{300} = \frac{100}{900} [/tex]
[tex]x = \frac{300 \times 100}{900} = 33 \frac{1}{3} [/tex]
13)
[tex] \frac{13}{x} = \frac{10}{9} \\ \\ x = \frac{13 \times 9}{10} = 11 \frac{7}{10} [/tex]
