solve the equations to find z and w, expressed in a + ib form
z + (1 - i)w = 2i
w + (1 - i)z = 1
these are the system of linear equation in two variable w and z(i agree with mr.fantastic that this is wrong representation with complex numbers to use 'z' and 'w' as numeral variables). try to solve them by any method which is suitable to you like substitution method,Elimination method etc.and put i^2=(-1) where require.
if you have any confusion, look at spoiler;i have used Elimination method in spoiler.