c – 4500 = 7200 + 2800
c = 2800 + 7200 + 4500
c = 14500
x – 4500 = 7200 – 2800
x = – 2800 + 7200 + 4500
x = 8900
4500 – z = 7200 – 2800
– z = – 2800 + 7200 – 4500
-z = -100
z = 100
c – 4500 = 7200 + 2800
c = 2800 + 7200 + 4500
c = 14500
x – 4500 = 7200 – 2800
x = – 2800 + 7200 + 4500
x = 8900
4500 – z = 7200 – 2800
– z = – 2800 + 7200 – 4500
-z = -100
z = 100