Question 548516
plane 	speed	=	203	km/h													
wind speed	=	x	km/h					
against wind   		=	203	-	x 			
with wind  		=	203	+	x 			
Total Time=	11.00	hours  										
Time against + time with = 11 
666/(203-x)+769	/(203+x	)=11		
666(203	+x)+769(203-x)=	11		
135198+666x+156107-769x	=11(203^2-x^2)	
135198+666x+156107-769x	=453299-11x^2

11x^2-103x-161994=0

Find the roots of the equation by quadratic formula									
									
a=11	,b=-103	,c=-161994		
									
b^2-4ac=	10609	+	7127736						
b^2-4ac=	7138345		
{{{	sqrt(	7138345	)=	2671.77	}}}	
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}									
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}									
x1=(	103	+	2671.77	)/	22				
x1=	126.13								
x2=(	103	-2671.77	) /	22					
x2= 	-116.76								
Ignore negative value									
wind  	speed	126.13	mph