tolong bantu kasih caranya dong

m x a = F
m x 2 = (50-20)
m = 30÷2 = 15 kg

(15+5) x a = (50-20)
20 x a = 30
a = 1,5 m/s² (C)

m = 30 : 2
    = 15 kg

15+5 = 20kg
 
30/20 = 1,5m/s²