These would have infinite solutions because this is a slope-intercept equation. Since you are provided with the y-intercept in both, you can put anything in for the slope and it will work.
Hope this helps!
The lengths of two sides is not enough information to determine a unique triangle. There are an infinite number of possible correct answers. If 'x' is the length of the third side, then its length can be anything between 3 and 13.
