Which respond fast please.

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

Okay so i didn't get this problem petro bought 8 tickets to a basketball game he paid a total of $200 write an equation to determine whether each ticket cost $26 or $28 so i didn't get this question so yeahyou have a good day.

$5400 is? invested, part of it at 11? % and part of it at 8? %. for a certain? year, the total yield is ? $522.00. how much was invested at each? rate?