Question 1179658
A plane traveling with the wind flew 1312.5 mi in 5.25 h. Against the wind, the plane required 6.25 h to fly the same distance. 

Plane	speed	=x	mph	in still air				
wind	speed	=y	mph					
against wind  x-y		6.25	hours					
with wind  x+y		5.25	hours					
								
Distance = same=		1312.5	miles					
t=d/r								
1312.5	/	(	x	-	y	)=	6.25	
1120.00	/(	x	+	1	y)	=	5.25	
1.00	x		1.00	y	=	179.20	....................1	
1312.5	/	(	x-	1	y	)=	5.25	
1312.50	/(	x	-	1	y)	=	5.25	
1.00	x	-	1.00	y	=	250.00	...............2	
Multiply (1) by	1.00							
Multiply (2) by	1.00							
we get								
1	x	+	1	y	=	179.2		
1	x	-	1	y	=	250		
2	x	=	429.2					
/	2							
x	=	214.6	mph