can someone please help me ill give brainest? Will the velocity of the book change as it moves across the surface WITH friction? Explain your answer.

Friction always acts to oppose any relative motion between surfaces.

If we push on the book with a force of less than 5 N, the book won't move, because the frictional force will exactly balance the force we apply. If we push with a 1 N force, a 1 N frictional force opposes us.

Idid the calculation and i get 875,000,000 which can be written as 8.75 x 10^6?

Yeah, but what are you trying to ask?