EXPLANATION
Since the two planes are 3400 miles apart, and their speed differs by 80 mph, we can apply the following relationship:
2660 / 4 = 665 mph
Assuming that x is the speed of the slower plane and y is the speed of the faster, we have:
(1) x + 65 = y
(2) x + y = 665 [Combined speed of both planes]
Plugging in (1) in (2):
x + (x + 65) = 665
Removing the parentheses:
x + x + 65 = 665
Adding like terms:
2x + 65 = 665
Subtracting -50 to both sides:
2x = 665 - 65
Subtracting numbers:
2x = 600
Dividing both sides by 2:
x = 300
Plugging in x=315 into (1):
300 + 65 = 365
In conclusion, the speed of both planes is:
Slower plane = 300 mph
Fastest plane = 365 mph
