What is the density if the length is 2.5 cm the volume 15.6 cm and the mass is 145 g

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

What rotation was applied to triangle def to create d’e’f’?

Two trains leave stations 546 miles apart at the same time and travel toward each other. one train travels at 95 miles per hour while the other travels at 115 miles per hour l. how long will it take for the two trains to meet