Tolong jawab pakai cara yaa..

B = lama × % × tab. awal
300 = x/12 × 5/100 × 4.000
300 = x/12 × 5 × 40
300 = x/3 × 5 × 10
300 = 50/3
300 × 3 = 50x
900 = 50x
900/50 = x
18 = x

18 bulan


maaf ya kalo salah