I have exams on number theory coming up.And this is something I don´t really understand, how to handle such tasks. Could anyone please explain it to me in a very understandable way (just studying primary school teaching..) Thank you folks.
If 7/2a +b, then 7/ 100 a +b.
I could transform it to 100a+b= 7l and 2a+b= 7k But how to prove now? Also the task says " after proving the divisibility, show one rule of divisibility for seven. How does this work? Thank you so much.Looking forward to your answers. Sophia