<PRE><B>Question 871890</B>
First Part	x			km 						
Second Part	-x		540	km 						
Total time		8	hours							
First Part	time 	60	/	x						
Second Part	time 	80	/	(-	540	-	x)			
										
Time first part + time second part =			8	hours						
										
x/	60	+(	540	-x)/	80	=	8			
										
multiply the equation by the LCD										
we get										
										
80	x+	60	(	540	-x)=	8	*	60	*	80
										
80	x+	32400	-	60	x 		=	38400		
20	x+	32400		=	38400					
/	20									
4	x  	1620	x+	=	1920					
4	x  	=	1920	-	1620					
4	x  	=	300							
	x=		75	km 	First part					
</PRE>