Answer: D. [tex] 7t^2+3+6[/tex]
Step-by-step explanation:
Given: 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.
[tex]a(t)=5t+2\\\\b(t)=7t^2-2t+4[/tex]
The expression that describes the total cost of manufacturing both products will be ,
[tex] a(t) + b(t)=5t+2+7t^2-2t+4[/tex]
Combining like terms, we get
[tex] a(t) + b(t)=7t^2+5t-2t+4+2\\\\\Rightarrow\ a(t) + b(t)=7t^2+3+6[/tex]
