Answer fast with an explanation and kinda fast

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

The table shows the balance of a money market account over time. write a function that represents the balance y (in dollars) after t years.

The difference between two numbers is one. three times the larger number minus two times the smaller number is 9. what are the two numbers