[tex]\frac{a}{4} = \frac{b}{7}[/tex] => 7a = 4b => a = [tex]\frac{4b}{7}[/tex]
inlocuim a-ul:
[tex]\frac{4b}{7}[/tex] + 8 [tex]\frac{4b}{7}[/tex] + [tex]\frac{56}{7}[/tex] [tex]\frac{4b + 56}{7}[/tex]
----------- = ------------- = -----------
b + 14 b + 14 b+ 14
Trecem 7-le de jos sub linie, ii schimbam semnul (din impartit la 7 devine ori 7)
si avem:
4b + 56 4(b+14) 4
-------------- = -------------- si putem simplifica cu b + 14 deci ramane ----------
7(b + 14) 7 (b+14) 7
Raspuns: C)
