I’m having doubts about my homework, am I correct?

Explain :)

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

Ineed me i stuck and i don’t want to get it wrong

Apackage of orgainc strwberries costs $1.50 while there in season and $2.25 when not in season what the percent increase