Question 498174
first part	35	miles													
second part	9	miles													
															
speed in first part	x			mph											
speed second part	x		-5	mph											
Total rowing time		2	hours												
Time first part		35	/	x											
Time second part		9	/	(	x	-5	)								
															
Time first part + time second part =			2	hours											
															
35	/	x				+	9	/(x	-5	)	=	2			
LCD =	(	x	+	0	)*	(x	-5	)							
multiply the equation by the LCD															
we get															
35	*	(x	-5	)+	9		x				=	2			
35	x	-175	+	9	x				=	2	X^2		+	-10	x
54	x	-175	=	2	X^2										
2	X^2	-54	x	175			=	0							
2	X^2+	-54	x+	175	=										
/	2														
1	X^2	-27	x	87.5	=										
															
Find the roots of the equation by quadratic formula															
															
a=	1	b=	-27	c=	87.5										
															
b^2-4ac=	729	-	-350												
b^2-4ac=	379			{{{sqrt(	379	)}}}=	19.47								
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}															
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}															
x1=(	27	+	19.47	)/	2										
x1=	23.23	mph												
x2=(	27	-19.47	) /	2											
x2= 	3.77	mph

													
First Part speed = 23.23 mph
Second part speed = 18.23 mph

m.ananth@hotmail.ca