Question 908100
plane	speed	=x	mph						
wind   	speed	=y	mph						
against  	wind   	4	hours						
with	wind   	3	hours						
									
Distance against 		960	miles	distance with 		960	miles		
t=d/r	against	wind   		-					
960.00	/	(	x	-	y	)=	4.00		
4.00	(	x	-	y	)	=	3.00		
4.00	x	-	4.00	y	=	960.00	....................1		
									
960.00	/	(	x	+	y	)=	3.00		
3.00	(	x	+	y	)	=	960.00		
3.00	x	+	3.00	y	=	960.00	...............2		
Multiply (1) by	3.00								
Multiply (2) by	4.00								
we get									
12.00	x	+	-12.00	y	=	2880.00			
12.00	x	+	12.00	y	=	3840.00			
24.00	x	=	6720.00						
/	24.00								
x	=	280.00	mph						
									
plug value of x in (1)				y					
4.00	x		-4.00	y	=	960.00			
1120.00			-4.00	-1120.00	=	960.00			
-4.00	y	=	960.00						
-4.00	y	=	-160.00	mph					
	y	=	40.00						
plane	speed	280.00	mph						
wind   	speed	40.00	mph						
									
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