Answer:
The slower plane is flying at 175 miles per hour and complete the trip in 10 hours
The faster plane is flying at 250 Miles per hour and complete the trip in 7 hours
Explanation:
Let s= speed of the slower plane s+75= speed of the faster plane
The time it takes the slower plane to make the flight = 1750/s
The time it takes the faster plane to make the flight is=1750/(s+75)
The difference in these two times is 3 hours
1750/s - 1750/(s+7)=3
{(s+75) / (s+75) * (1750/s)} - {(s/s) * (1750/s+75)} =3
(1750s+131250 / s^2+75s) - (1750s/s^2+75s) =3
1750s+131,250-1750s / s^2+75d =3
131,250 / s^2+75s = 3
Cross product
131,250=3(s^2+75s)
131,250=3s^2+225s
43,750=s^2+75s
s^2+75s-43,750=0
Solve the quadratic equation
x= -b +or- √b^2-4ac / 2a
a=1
b=75
c= -43750
x= -b +or- √b^2-4ac / 2a
= -75 +or- √(75)^2 - (4)(1)(-43750) / (2)(1)
= -75 +or- √(5625) - (-175,000) / 2
= -75 +or- √180625) / 2
= -75 +or- 425 / 2
x= -75 + 425/2 OR -75- 425/2
=350/2 OR -500/2
x=175 OR -250
We will ignore the negative sign because the planes are not flying Backward
The slower plane is flying at 175 miles per hour and complete the trip in 1750/175= 10 hours
The faster plane is flying at 250 Miles per hour and complete the trip in 1750/250= 7 hours