tolongg dijwb yaa,pake caraa

Pembahasan :

F × 80 cm = W × (100 cm - 80 cm)
F × 80 cm = W × 20 cm
F × 80 cm = 400 N × 20 cm
F = 400 N × 20 cm / 80 cm
F = 400 N × 1/4
F = 100 N

Jawaban : C.