Which of the following are subspaces of r[infinity]? if not, explain why. a) all sequences such that |xj+1| ≥ |xj | for each j. b) all convergent sequences: the xj has a limit as j → [infinity]. c) all arithmetic progressions: xj+1 − xj is the same for all j. d) all geometric progressions: (x1, k x1, k2 x1, . .) allowing all k and x1

3. solve the given inequality and graph the solution on a number line.

The function a represents the cost of manufacturing product a, in hundreds of dollars, and the function b represents the cost of manufacturing product b, in hundreds of dollars. a(t) = 5t + 2 b(t) = 7t - 2t +4 find the expression that describes the total cost of manufacturing both products, a(t) + b(t). a. 7t^2 - 7t + 2 b. 7t^2 + 3 +6 c. 7t^2 + 7t - 6 d. 7t^2 - 3t + 6

15/16 as a decimal rounded to the nearest hundredth