Question 424941
let unit cost of electricity be $x
let unit cost of gas be $y

500x+100y=88.............1		
400x+150y=76.............2		
									
multiply (1)by -3							
Multiply (2) by 2							
-1500x-300y=-264			
800x+300y=152			
									
Add the two equations							
-700x=-112			
/-700								
x=0.16	electricity unit cost	16 cents		
									
plug value of x	in (1)					
									
500x+100y=88			
80+100y	=88			
100y=88-80	
100y=8			
y=0.08	gas unit cost  8 cents