Your question does not make sense.
Infinite, both equations are equivalent and all possible solutions can be represented on the graph y = 4 - x
There are no whole solutions
many solutions
There are 120 solutions.
1 solution
1
many solutions
Two solutions and they are:- x = 0 and y = 3
2
It has two equal solutions of 2
One solution.
zero solutions. If you plot these two lines, you will see that they are parallel and do not intersect.