[a+b+c+d+e]:5=336
=>a+b+c+d+e=5×336
=>a+b+c+d+e=1680
a/2=b/3=c/12=k
=>a/2=k=>a=2k1
=>b/3=k=>b=3k1
=>c/12=k=>c=12k1
=>c×3=k=>c=k2/3
=>d×4=k=>d=k2/4
=>e×10=k=>e=k2/10
=>2k1+3k1+12k1+k2/4+k2/10=1680
=>17k1+k2/4+k2/10=1680
=>680k1/40+10k2/40+4k2/40=1680
=>[680k1+14k2]/40=1680
=>680k1+14k2=1680×40
=>680k1+14k2=67200
=>metoda prin variante