# Question 9ff49

May 25, 2017

The velocity of two planes are respectively 100mph and 200mph.

#### Explanation:

Suppose,one planes speed and anothers are respectively x mph and(x+140) mph.
In one hour first plane goes x mile and the other (x+140) mile.
According to problem,
x²+(x+140)²=(260)²
=>2x²+19600+280x=67600
x²+140x-24000=0#
$\left(x - 100\right) \left(x + 240\right) = 0$
The velocity cannot be negative so the velocity of the plane is 100 mph.
The other's is 200 mph.