a+c=17 920
c=[tex] \frac{28a}{100} [/tex]
[tex]a+ \frac{28a}{100}=17 920 [/tex]
inmultim a si 17920 cu 100, ptu a aduce la acelasi numitor
[tex] \frac{100a}{100}+ \frac{28a}{100}= \frac{1792000}{100} [/tex]
100a+28a=1792000
128a=1792000
a=1792000:128
a=14000
14000+c=17920
c=17920-14000
c=3920
14000 adulti si 3920 copii