Answer:
1) 
2) 
3) 
4) 40
5) 
Step-by-step explanation:
1) Distribute the negative sign that is outside the parentheses and then you must add like terms, as following:

2) According to the Product property of exponents, when you multiply powers with the same base, you must add the exponents. Then:

3) Apply the Distributive property and the Product property of exponents. Then, you obtain:

4)
is a square of a sum, then, by definition you have:

Then:

The coefficient of the second term is the number in front of the variable <em>a.</em> Then, the answer is: 40
5) Apply the Distributive property and the Product property of exponents, then, oyou must add the like terms:
