I need a general solution and not a particular.

(a) 3x + 6y = 11

(b) 6x ≡ 11 (mod 15)

(c) 6x ≡ 9 (mod 11)

What i do not understand is that the usuall way that ive been learned to solve this does not work. since the greateast common divider at a is 3. But 3 cant be multiplied to 11 with a integer

Any tips or solutions please write. Best regards

Bargot Sep 30, 2018