D. The economy of the Soviet Union was falling behind that of other major industrialized nations.
Answer: A
Step-by-step explanation:
Consider the polynomial 
It has three terms and their greatest common factor is 
Since
then
(you write in brackets the same sign as the corresponding term has).
Answer: correct choice is D.
For the addition problem 1/4 would turn into 2/8 and the 3/8 would stay the same therefore it would be 2/8 + 3/8 =5/8. Then for the subtraction problem 1/4 would turn into 2/8 and 3/8 would stay the same therefore it would be 2/8 - 3/8 =1/8
