Answer: 0
Step-by-step explanation: 21/7=3, so there is no change.
Answer:
Which one ?
Step-by-step explanation:
The original area of a face would be a^2. Now that you added b to the edge, the new area of each face would be (a+b)^2. To find how much the are increased, subtract a^2 from (a+b)^2.
So the answer is b(2a+b)