Question

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Answer 1

Questions 1 and 3 look right, but try looking at question 2 again.
There is one solution if the two lines cross, if they're parallel there are no solutions and if they're the same equation there are infinite solutions.

Answer 2

Yes, you can verify that by graphing them if you want. Of course the easiest way is to put them in the same form.
y = x + 1
y = (1/2)x + 3

Answer 3

No problem :)