Answer:
Be careful what you wish for.
Step-by-step explanation:
its (a) because (a) is C(x)=3x4+30x and 9+21 is 30 so its 3x2+30
8.3
Step-by-step explanation:use law of cosine
solve equation
substitute
simplify
6 minutes per mile.
As in, 30/5= 6