Question

Aflati x asfel incat a ) cu bara de asupra toate ( 51x,2)=1 b) (x27,3)=1 c) (7x2,5)=1 d) (3x,5)=1

Answer 1

a)   x={1;3;5;7;9}
b)   x={1;2;4;5;7;8}
c)   x={0;1;2;...;9}
d)   x={1;2;3;4;6;7;8;9}

Answer 2

Doua numere sunt prime intre ele daca  c.m.m.d.c. al lor este egal cu 1.
a) Daca (51x ; 2)=1 atunci x∈{1,3,5,7,9} 
b) Daca (x27 ; 3)=1 atunci x∈{1,2,4,5,7,8} 
c) Daca (7x2 ; 5)=1 atunci x∈{0,1,2,3,4,5,6,7,8,9}
d) Daca (3x  ; 5 )=1 atunci x∈{1,2,3,4,6,7,8,9}