can someone tell me where i have gone wrong i am stuck on this last question, i am pretty sure i have done something wrong:

I have to do product over sum to combine the two equations

Z1 X Z3

-------

Z1 + Z3

Z1=10+J30 Z3=2-J20

Z1= 31.6 <71.5 degrees

Z3= 20 <84.2 degrees

(31.6<71.5)(20<84.2) 632<155.7

--------------------- = ------------

(10+J30)+(2-J20) 12+j10

-576 + J260

= ------------

12 + J10

(-576+J260)(12-J10)

= ---------------------

(12+J10)(12-J10)

-6912+J5760+3120-J2600

= -------------------------

144-120J+120J-J^2 100

-3792 + J3160

= ---------------

144-100

Have i gone wrong as this does not seem correct?