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Answer this question! 30 points and brainliest! only if you know the answer.

Select the correct answer. joshua likes to read. he read 6 books when he was 6 years old. every year he doubled the number of books he read the previous year. how many total books did he read between the ages of 6 and 10? a. 60 b. 90 c.186 d.187

Find the greatest common factor of the followig monomials 21u^5v,3u^4v^6, and 3u^2v^5