tolong donnnnngggg gak bisa niehh

5.
Vo= 20 km/jam. (kecepatan pergi = PQ)
t= waktu pergi
S = 20 × t

V = 16 km/jam ( kecepatan pulang = QP)
to = t+1/4 jam
S = 16 (t+1/4)

20t = 16(t + 1/4)
20t = 16t + 4
4t = 4
t = 1 jam

maka waktu QP :
S = 16 × 5/4 = 20 km
t = S : V = 20 : 16 = 1 jam 15 menit

6.
berbanding terbalik, berarti
P = 1/V
PV = 1, atau
P1V1 = P2V2
30.40 = P2.(40 - 25%.40)
1200 = P2(75%.40)
1200 = P2. 30
P2 = 40 psi