Răspuns:
[tex] \frac{x}{5} = \frac{7}{2} \\ x \times 2 = 7 \times 5 \\ 2x = 35 \\ x = \frac{35}{2} [/tex]
[tex] \frac{4}{x} = \frac{9}{5} \\ 9x = 4 \times 5 \\ 9x = 20 \\ x = \frac{20}{9} [/tex]
[tex] \frac{11}{5} = \frac{x}{10} \\ 5x = 110 \\ x = \frac{110}{5} \\ x = 22[/tex]
[tex] \frac{4}{13} = \frac{1}{x} \\ 4x = 13 \\ x = \frac{13}{4} [/tex]