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!
Answer is x=24
...hope it helps
All you need to do for this is remove the parenthese and your answer will be 
because that's the furthest it can be simplified.
The first, fourth and fifth ones are linear.
The second, third and sixth are all nonlinear.
You can tell this by the fact that their lead exponents are not 1.
