running the commands above, the maple provides the following answer,

x1=3/4+(1/12)sqrt (81+192 I *y-144y^2)

x2= 3/4-(1/12)sqrt (81+192 I *y-144y^2)    ,which is different from the solution the problema, z=0 

and  z=3/2.

running the commands above, the maple provides the following answer,

x1=3/4+(1/12)sqrt (81+192 I *y-144y^2)

x2= 3/4-(1/12)sqrt (81+192 I *y-144y^2)    ,which is different from the solution the problema, z=0 

and  z=3/2.