[tex] \frac{x}{21} = \frac{2}{3} [/tex]
[tex]x \times 3 = 2 \times 21[/tex]
[tex]3x = 42[/tex]
[tex]x = \frac{42}{3} [/tex]
[tex]x = 14[/tex]
[tex]∴ \: the \: proportional \: fractions \: are \ \: : [/tex]
[tex] \frac{14}{21} = \frac{2}{3} [/tex]
[tex] \frac{14}{8} = \frac{x}{20} [/tex]
[tex]14 \times 20 = 8 \times x[/tex]
[tex]8x = 280[/tex]
[tex]x = \frac{280}{8} [/tex]
[tex]x = 35[/tex]
[tex]∴ \: the \: proportional \: fractions \: are \ \ \: : [/tex]
[tex] \frac{14}{21} :: \frac{35}{20} [/tex]