dau coroana @
a supra b=7 supra 2 si b=4 supra 21
a=?


Răspuns :

[tex] \frac{a}{b} = \frac{7}{2} [/tex]

[tex]2a = 7b[/tex]

[tex]2a = 7 \times \frac{4}{21} [/tex]

[tex]2a = \frac{28}{21} [/tex]

[tex]2a \times 21 = 28[/tex]

[tex]42a = 28[/tex]

[tex]a = \frac{28}{42} [/tex]

[tex]a = \frac{14}{21} [/tex]