Answer:
see explanation
Explanation:
in (1) and (2) use the rule of exponents
 =
 = 
 , then
 , then
(1)
 =
 = 

(2)
 =
 = 

question (3) involves expanding a binomial
(B - 4)²
= (B - 4)(B - 4)
each term in the second factor is multiplied by each term in the first factor, that is
B(B - 4) - 4(B - 4) ← distribute both parenthesis
= B² - 4B - 4B + 16 ← collect like terms
= B² - 8B + 16