Question 839188
the amount invested in two advertising agencies is 100000. one investment yields 10% and the annual income from this investment is 5000 less than the annual income from the other investment yield 8%. Find the about invested at each rate 

x at 10%
y at 8%

total invested

x+y=100000.....................(1)

Interest from 8% investment - interest from 10% investment = 5000
8y/100 - 10x/100 = 5000

multiply by 100

8y-10x=500000.................(2)

1	x	+	1	y	=	100,000	.............1	
Total value								
-10	x	+	8	y	=	500,000	.............2	
Eliminate	y							
multiply (1)by		-8						
Multiply (2) by		1						
-8	x		-8	y	=	-800,000		
-10	x	+	8	y	=	500,000		
Add the two equations								
-18	x				=	-300,000		
/	-18							
x	=	16,667						
plug value of			x	in (1)				
1	x	+	1	y	=	100,000		
16,667		+		y	=	100,000		
				y	=	100,000		-16,667
				y	=	83,333		
				y	=	83,333		
x=	16666.67							
y=	83333.33							
m.ananth@hotmail.ca