Question

determinati numerele a si b, stiind ca (a,b)= 7 si a+b = 35​

Answer 1

(a,b) = 7 => a=7x, b=7y

Unde (x,y)=1, x,y∈N*

a+b=35 <=> 7x+7y=35

=> 7(x+y)=35

x+y=5

x,y≠0 => x,y≠5

x=1, y=4 => a=7, b=28

x=2, y=3 => a=14, b=21

x=3, y=2 => a=21, b=14

x=4, y=1 => a=28, b=7

S = {(7,28), (14,21), (21,14), (28,7)}