stay off if you dont know and if you cant show work.. Which expression represents the difference (6b+9)−(7b−4)? show your work.

20 only answer if 100% sure most high school-aged teens are very active. a. true b. false

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

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