You can
put this solution on YOUR website!
The inverse of 'if p then q' is 'if (not p) then (not q)'
p = I do not change my car’s oil
q = my car will have engine trouble
not p = I change my car’s oil
not q = my car will not have engine trouble
So the inverse of the original statement is:
If I change my car’s oil then my car will not have engine trouble (the last one in your list).