x :12= a rest 4, x= 12a+4, x-4=12a
x:15= b rest 4, x= 15b+4, x-4=15b
x:18= c rest 4, x= 18c+4, x-4=18 c
adica x-4 e cel mai mic multiplu comun al nr 12, 15, 18
calculez c.m.m.m.c al nr 12,15,18
12=2^2*3
15=3*5
18=2*3^2
c.m.m.mc=2^2*3^2*5=180
x-4=180
x=180+4
x=184
b) a*6=b*8=k
a+b=70
a*6=k, a=k/6
b*8=k, b= k/8
k/6+k/8=70
8k/48+6k/48=70*48/48
renunt la numitor
14k=70*48
k=70*48/14=240
a=240/6=40
b=240/8=30
nr sunt a=40 si b=30
