Question 552794
Sam	x											
Gabriel	x	+	16									
	4	years later										
Sam	x+4									
Gabriel	x+16+4	=x+20		
Gabriel	2	times older										
x+20=2(x+4)	
x+20=2x+8			
2x-x=20	-8				
x=12							
/	1									
x=12 years		Sam							
x+16=	28	years		Gabriel