Jawabanmu

2014-04-27T17:36:07+07:00
BD^2 = AD × CD 12^2 = (25-CD) × CD 144 = 25CD - CD^2 CD^2 - 25CD + 144 = 0 (CD - 16)(CD - 9) = 0 CD = 16 atau CD = 9 B