Question 815901
x+y = 21
y = x+3


--------------


x+y = 21


x+x+3 = 21


2x+3 = 21


2x = 21-3


2x = 18


x = 18/2


x = 9


y = x+3


y = 9+3


y = 12


-------------------------------------------------------


Final Answer: 


The two pieces are 9 yards and 12 yards long.