Answer:
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Step-by-step explanation:
Answer:
b
Step-by-step explanation:
speed of plane flying east = x
speed of plane flying west = x+75
total speed = 2x+75
distance after 4 hours ( 7-3) = 8x+300
8x+300 = 5460
8x = 5160
x = 5160/8 = 645
speed of plane flying east = 645 km/h