Question 460139
2a=b+c
4b=a+c
a+b+c=5625

..
2a-b-c=	0--------------	1
-a+4b-c	=0--------------2
a+b+c=5625--------------3
																
consider equation 1 &2				Eliminate b												
Multiply 1 by	4								
Multiply 2 by	1									
we get																
8a-4b-4	c=0						
-a+4b-c=0						
Add the two 																
7a-5c=0	-------------				4	
consider equation 2 & 3				Eliminate b									
Multiply 2 by 	1								
Multiply 3 by	-4												
we get 																
-	a	+	4	b	+	-	c	=	0							
-4	a		-4	b		-4	c	=	-22500							
Add the two 																
-5a-5c=	-22500	-------------5				5		
Consider (4) & (5) Eliminate a													
Multiply 4 by	5												
Multiply (5) by	7												
we get																
35	a		-25	c	=	0										
-35	a		-35	c	=	-157500										
Add the two 																
-60	c	=	-157500										
/	-60															
c	=	2625														
																
Plug the value of c in						5										
-5	a		-13125		=	-22500										
-5	a	=	-9375													
a	=	1875														
plug value of a & c in					1											
3750		-	b	+	-2625	=	0									
-1	b	=	-3750	+	2625	+	0									
b=	1125											
a-b=750