Question 470798
first part	x	mph										
second part	-5	mph										
												
first part	73	miles										
second part	14	miles										
												
speed in first part	x			mph								
speed second part	x		-5	mph								
Total rowing time		3	hours									
Time first part		73	/	x								
Time second part		14	/	(	x	-5	)					
												
Time first part + time second part =3	hours								
												
73/x+14/(x-5)=3
LCD =x*	(x-5)				
multiply the equation by the LCD												
we get												
73*(x-5)+14x=3
73x-365	+14x=	3X^2-15x	
102x-365	=3x^2							
3X^2-102	x+365			=	0				
3x^2-102	x+365=0						
/3											
x^2-34x+	121.67=	0						
												
Find the roots of the equation by quadratic formula												
												
a=	1	b=	-34	c=	121.67							
												
b^2-4ac=	1156	-	-486.68									
b^2-4ac=	669.32
{{{sqrt(	669.32	)}}}=	25.87					
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}												
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}												
x1=(	34	+	25.87	)/	2							
x1=	29.94											
x2=(	34	-25.87	) /	2								
x2= 	4.06		
																			
x	=	29.94	mph first part
24.94 mph second part						
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