Question 425919
Tom's age	x											
Jack's age	x	+	20									
4 years later										
Tom's age	x	+	4									
Jack's age	x	+	20	+	4		=	x	+	24		
Jack is 	3	times older										
x+24=3(x+4)	
x+24=3x	+12			
3x-x=24	-12				
2x=12							
/2									
x=	6		Tom's age							
x+20 =26 years		Jack's age