Question 477748
train  		x				150	miles			
Bus		x	-20			120	miles			
										
t=d/r					
150	/	x=120/(	x-20)
Cross multiply										
150	(	x	+	-20	)	=	120	*	x	
150	x	+	-3000	=	120	x				
120	x		-150	x	=	-3000				
-30	x	=	-3000							
/	-30									
x 	=	100	train  	mph						
		80	Bus	mph