Question

by applying force in the direction opposite to the direction of the motion of a body we can _______ its speed​

Answer 1

Answer:

THE SPEED WILL ''DECREASE''

HOPE THIS HELPS◉‿◉

Answer 2

Answer: reduce

Suppose, your friend is pushing you forward and you move with a constant speed, but when you try to stop yourself by applying a force on the ground,in negative direction, (i.e opposite to the force applied by your friend) your speed will slow down.

i.e Reduce.