Answer is B
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Answer:
10i
Step-by-step explanation:
Since i^2 = -1, and 1000 = 10^3, we can instinctively guess that the answer is 10i. We can validate this by cubing it, yielding 1000i^3, or -1000i.
Answer:

Step-by-step explanation:
Set up a proportion with corresponding sides. The two sides marked with a small line in them represent that those sides are equal. Therefore, the side marked 30 is broken into two lines of equal length (each 15).
Thus, we can set up the following proportion:

I am going to assume D is the correct answer, hope I'm right!