Q2:

This means:

Solve this diofanthine equation by first constructing the help equation, HE.

HE:

You say you know Euclides Algorithm. Working it backwards can be tricky, and obv the correctnes of the solution depends on not making any mistakes here.

So we end up with a solution to HE being

Now multiply both the x-solution and k-solution with 17.

So you get ONE solution for

This solution is:

Now we write:

Since we are often interested in the positive solutions we get

Q3. Try doing the same with Q3, and then you have to find an x satisfying both these equations.