Answer:
2400 km
Step-by-step explanation:
distance=rate*time
d=rt
d=(800)(t+1)
d=(1200)(t)
the right sides are both equal to d so set them equal to each other
800(t+1)=1200(t)
800t+800=1200t
800=1200t-800t
800=400t
t=800/400
t=2 hours
d=1200*2
d=2400 km