Jawabanmu

2014-02-13T18:13:52+07:00
 U_{4} = 2 (4)^{2} - 5
 U_{4} = 2 . 16 - 5
 U_{4} = 32 - 5
 U_{4} = 27

 U_{5} = 2 (5)^{2} - 5
 U_{5} = 2 . 25 - 5
 U_{5} = 50 - 5
 U_{5} = 45

 U_{4}  +  U_{5} = 27 + 45
 U_{4}  +  U_{5} = 72

jika terdapat kesalahan mohon dimaafkan :)