Aflati numerele a;b si c daca [tex]\frac{a}{3}=\frac{b}{4}[/tex] si [tex]\frac{b}{6}=\frac{c}{5}[/tex] , iar a+b+c=62

Cat de repede se poate!!!
Multe puncte+coroană!


Răspuns :

a/3 = b/4
a=3b/4

b/6=c/5
c=5b/6

a+b+c=62
3b/4 + b + 5b/6=62
9b/12 + 12b/12 + 10b/12=62
31b/12=62
b= (12×62)/31
b=12×2
b=24

a=3b/4=72/4=18
c=5b/6=120/6=20
Baftă!
4a=3b=>a=3b/4
5b=6c=>c=5b/6
a+b+c=62
3b/4+b+5b/6=62 (aducem la acelasi numitor care este 12)
9b/12+12b/12+10b/12=62
31b/12=62 
si l=>b=(12×62)/31 l=>b=24
a=3b/4 l=>a=72/4 l=>a=18
c=62-(a+b)
c=62-(18+24)
c=62-424
c=20