4+(−7) is 7 units from 4, in the negative direction (that is, to the left of 4)
The old fare was "x"
then it got bumped up by 15%, and the new price is x + 15% of x,
so.. one could say, that "x" is the 100%, then you add a 15% to
it, to get 600
thus

solve for "x"
Silver stars are worth 2 and gold stars are each worth 5
Look below!
2(-2)(7)-3(-2)
-28-(-6)
(Don't forget that when you have two negative signs next to each other, you can make it addition)
SO, -28+6
=-22
Hope that helped!