Write in expanded form.

Example:
1. 2(2)(2)(2)(2)(2) = 2⁶
(2x)⁴ = (2x)(2x)(2x)(2x)

2. (3a)(3a)(3a)(3a) = ?
(xy)⁷ = ?

3. (-4)(-4)(-4)(-4)(-4) = ?
(-ab)⁶ = ?

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