For the first bubble or circle to fill in, the answer is Cx. So you have the proper answer here. Nice work. The pq turns into qp by the commutative property of multiplication
The answer to the second bubble is Cx for similar reasons as before. Now we have xy turn into yx
The third bubble's answer is C+ (commutative property of addition) because qp+yx swaps to yx+qp
The answer for the fourth bubble is D. You are correct.
The answer for the last (fifth) bubble is Ax to indicate "associative property of multiplication". We are simply regrouping terms when multiplying
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In summary the answers from left to right are: Cx, Cx, C+, D, Ax
