I have attached the system I cannot figure out.please show work so I can see where I am messing up at...

1.)a + b + c = 2200 cars rented

.90a + .10b + .10c = a (which represents the total number of cars at Metropolis airport)

.05a + .80b + .05c = b (which represents the total number of cars at downtown)

Solve for the systems. (Hint: It will be easy if you solve for c in the first equation in terms of a and b to get c = 2200 - a - b to substitute c in the other two equations before solving)