Question 449422
Plane A	x mph	1400	miles					
Plane B	x+50 mph  1000	miles					
												
t=d/r	Time 	3 hours less							
1400/x=1000/(x+50)+3
1400/x-1000/(x+50)=3
LCD = x(x+50)										
Multiply by LCD												
1400(x+50)-1000x	=3x(x+50	)	
1400x+70000-1000*x=3x^2
-3X^2+250x+70000	=0					
Find the roots of the equation by quadratic formula			
a=	-3	b=	250	c=	70000				
b^2-4ac=	62500+840000									
b^2-4ac=	902500
{{{sqrt(	902500	)}}}=	950					
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}												
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}												
x1=(-250	+950)/-6	
x1=-116.67											
x2=(-250	-950)/-6								
x2=200									
Ignore negative value

Plane A speed = 200 mph
Plane B speed = 250 mph