Answer:
a)

b)

Explanation:
a)

1. Distribute the second power (2) outside the first pair of parenthesis:

=

2. Distribute the third power (3) outside the second pair of parenthesis:

=

3. Combine like terms:

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b)

1. Factor the number 6 (= 2 · 3):

2. Cancel the common factor (2):

3. Cancel out
in the numerator an denominator:

hope this helps!