Question 726435
5 years ago radha age was 7 times of her daughter.her age will be 3 times of her daughter in 5 years.then what is the present age of radha?


let daughter's age =x
Radha's age =y

5 years ago

y-5=7(x-5)
y-5=7x-35
y-7x=-30........................(1)

5 years later

y+5=3(x+5)
y+5=3x+15
y-3x=10.........................(2)

Eliminate	y							
multiply (1)by		-1						
Multiply (2) by		1						
7	x		-1	y	=	30		
-3	x	+	1	y	=	10		
Add the two equations								
4	x				=	40		
/	4							
x	=	10						
plug value of			x	in (1)				
-7	x	+	1	y	=	-30		
-70		+		y	=	-30		
				y	=	-30	+	70
				y	=	40		
				y	=	40		
x=	10						
y=	40						
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