1.88 = (6000 - u) / o
multiply both sides by o and we get:
1.88o = 6000 - u
solve for u
(1) u = 6000 - 1.88o
similarly with the other one
(2) u = 2000 + 2.33o........... (+) because Z = -2.33
solve simultaneously
6000 - 1.88o = 2000 + 2.33o
solve for o...then sub the value...