Question

(ab,80)=20
(75,ab)=15

Answer 1

(ab,80)=20 =>ab=Xx20 si 80=4x20; (X,4)=1, X si 4 sunt prime intre ele

(75,ab)=15=> ab=Yx15 si 75=5x15; (Y,5)=1, Y si 5 sunt prime intre ele

ab=[20,15]=2^2x3x5=60

ab=60 => ab=Xx20=60;  ab=3x20; (3,4)=1

                  ab=Yx15=60;   ab=4x15; (4,5)=1

R: ab=60

Answer 2

(ab,80)=20=>80-20=60
(75,ab)=15=>75+15=90