Jawabanmu

2014-09-10T07:14:52+07:00
U6  = a+ 5b =24 000
U10= a+ 9b =18 00.........
................................. (-)
             -4b= 6 000
b=  - 1500
a= 31 500

Un= a+(n-1)b

0 = 31 500 - 1500 n + 1500

1500 n = 33 000

n = 22