Does 9q + 7 also equal 7 + 9q ? (simplifying algebraic expressions)

Which of the following is the missing term, a2, of the geometric sequence in which a1=2 and a3=200

You invested $5000 between two accounts paying 4% and 9% annual interest, respectively. if the total interest earned for theyear was $350, how much was invested at each rate? $was invested at 4% andwas invested at 9%.

James adds two numbers a + b. sally adds the same two numbers but reverse the order b + a what property of addition assures us that james and sally will get the same sum