X=-36
5/6x-1/2x=1/3x
1/3x-3=-9
1/3x=-12
x=-36
a is the answer as the only change is the gradient being halved,
b would be if it was -1/2 and c would be1/2 x+1/2
It is about 3,000. There is no #4 on your picture, so I just answered number one because that is all I saw.