tolong jawab ya terimakasih

M ke km = 234 × 1000 = 234000
Jam ke menit = 234000 ÷ 60 = 3900

No. 19 sudah benar.
No. 20) 6 km - 3000 cm + 200 dm = ...cm
3000 cm = 30 m
200 dm = 20 m
6000 m - 30 m + 20 m = 5990 m

No. 21) 234 km/jam = .....m/menit
234 km/jam = 234.000 meter/60 menit = 3900 m/menit. Jawabnya a

No. 22) Luas trapesium
L= (15 + 22) * t